DOCSLIB.ORG

An Iron-Based Catalyst Enables the Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An Iron-Based Catalyst Enables the Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction doi.org/10.26434/chemrxiv.12582284.v1 An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction Chet Tyrol, Nang Yone, Connor Gallin, Jeffery Byers Submitted date: 29/06/2020 • Posted date: 30/06/2020 Licence: CC BY-NC-ND 4.0 Citation information: Tyrol, Chet; Yone, Nang; Gallin, Connor; Byers, Jeffery (2020): An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction. ChemRxiv. Preprint. https://doi.org/10.26434/chemrxiv.12582284.v1 By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates. File list (2) 20200623_CCT_ChemRxiv_Enantioselective.pdf (648.82 KiB) view on ChemRxiv download file 20200623_CCT_ChemRxiv_Enantioselective_ESI.pdf (7.74 MiB) view on ChemRxiv download file An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1- Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction Chet C. Tyrol,*a Nang Yone a, Connor F. Gallina and Jeffery A. Byersa By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura cross- coupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates. Introduction Since the renaissance of iron-based catalysts used for cross-coupling reactions were galvanized by the seminal work of Fürstner at the turn of the century,1 industrial and academic interest in these catalysts have increased due to the high abundance and low toxicity of iron as well as the unique reactivity that these types of catalysts afford.2–4 Fast reaction kinetics are often observed with iron-based catalysts, which leads to complementary reactivity compared to many nickel-based catalysts used for similar reactions.1,5 A particularly prolific area of cross-coupling reactions that has benefited from the development of iron-based catalysts are reactions involving alkyl halide electrophiles with organomagnesium,6–9 organozinc,10,11 organoaluminium,12 and most recently organoboron-based13–17 organometallic nucleophiles. These catalysts have demonstrated remarkable reactivity, especially for cross coupling reactions involving sterically demanding substrates and heteroaromatic boronic esters.18 Despite these rapid advancements, enantioselective cross-coupling reactions that utilize iron-based catalysts are exceedingly rare and have been greatly overshadowed by the tremendous achievements in enantioconvergent systems employing nickel-based catalysts.19 In fact, only three enantioselective cross coupling reactions that utilize iron-based catalysts have been reported.20–22 All of these reactions use a-haloesters as electrophiles and none of them use unactivated boronic esters as nucleophiles. With this report, we expand the nascent scope of enantioselective iron-based cross-coupling reactions and advocate for their value in chemical synthesis with the synthesis of enantioenriched 1,1-diarylalkanes (Figure 1). Blockbuster pharmaceuticals, such as Zoloft, Detrol and SGLT2 inhibitors all contain the chiral 1,1-diarylalkane motif while eliciting a range of physiological responses (Figure 1a).23 Despite the fact that one enantiomer of these drugs is often more potent,[24] they are either sold as racemates, mixtures of diastereomers,25 or are obtained in enantioenriched form as a result of a late stage resolution.[25,26] These tactics are a likely symptom of synthetic limitations that have prevented access to enantiomerically enriched 1,1-diaryl alkanes. Consequently, Figure 1 a) Pharmaceuticals containing the 1,1-diarylalkane motif. b) the enantioselective synthesis of the 1,1-diarylalkane subunit has Synthetic routes to enantiomerically enriched 1,1-diarylalkanes c) become a popular contemporary topic for synthetic organic Enantioconvergent Suzuki-Miyaura cross-coupling of benzylic chlorides [27] chemists. Current approaches toward such motifs include catalyzed by iron complexes supported by cyanobis(oxazoline) ligands. asymmetric hydrogenation of 1,1-diarylalkenes, [28,29], nucleophilic and radical additions to alkenes,[30–32] and stereospecific[33–35] as well as Since ligand modifications did not improve performance, 1 was [36,37] stereoconvergent cross coupling reactions (Figure 1b). A method used for the final optimization because the ligand in 1 is commercially that is noticeably absent from this list is a stereoconvergent Suzuki- available. In our original report, we found that an extra equivalent of Miyaura cross coupling reaction. Such a reaction would closely mimic ligand was needed to obtain high yields of the cross-coupled product at the ubiquitous Suzuki-Miyaura cross coupling reactions used in the the expense of slower reaction rates.17 We hypothesized that the extra pharmaceutical industry for the construction of C–C bonds between two ligand formed an off cycle homoleptic complex containing two 2 38 sp -hybridized substrates. Herein, we report the first enantioselective cyanobis(oxazoline) ligands, which extended catalyst lifetime by Suzuki-Miyaura cross-coupling reaction between benzylic chlorides and preventing catalyst aggregation. Since benzylic halides have weak unactivated arylboronic-pinacol esters that is made possible by carbon-halogen bonds that are more susceptible to homolysis, we capitalizing on the reactivity of an iron-based catalyst (Figure 1c). hypothesized that using extra ligand was detrimental for this class of electrophiles, leading to increased production of 3. Consistent with this hypothesis were higher yields of 2 with concomitant decreased yield of Results and discussion 3 for a reaction carried out without extra ligand (entry 13). Control Previously, we reported that iron-based complexes supported by experiments confirmed once again that 1,3,5-TMB led to higher yields, chiral cyanobis(oxazoline) ligands were competent catalysts for Suzuki- even without extra ligand (entry 14). Finally, enantioselectivity was Miyaura cross coupling reactions between alkyl halides and unactivated aryl boronic esters.17 Given that the method utilized a chiral catalyst and Table 1. Optimization of the Suzuki-Miyaura cross-coupling reaction tolerated secondary alkyl halides, we hypothesized that it would be between 1-chloroethylbenzene and 2-napthylboronic pinacol ester suitable for the stereoselective cross-coupling of secondary benzyl catalyzed by bis(oxazoline) iron complexes. halide electrophiles and arylboronic ester nucleophiles to give X O O R O O R4 3 enantioenriched 1,1-diaryl alkanes. R or R3 N N 4 N N Exploratory reactions between (1-chloroethyl)benzene and 2- R1 Fe R2 Fe Ph R R1 Ph 2 Cl Cl Cl naphthylboronic acid pinacol ester under our previously reported 1,4-11 12 17 conditions using cyano(bisoxazoline) iron(II) chloride complex 1 as the Fecat (10 mol%) Cl Ligand (10 mol%) * catalyst precursor and benzene as the solvent led to 1,1-diaryl alkane 2 O 1,3,5-TMB (1 equiv.) + + Ph B in 64% yield and with an enantiomeric ratio (er) of 74:26 (Table 1, entry (rac) O LiNMeEt (1.2 equiv.) Ph * Ph * 1). A competitive side product was compound 3, which results from the o-C6F2H4, rt, 24 h (1 equiv.) (2 equiv.) 2 3 homodimerization of the benzyl halide starting material. Importantly, [a] [b] [a] using the preformed iron complex was necessary to obtain 2 in high Entry Fecat R1 R2 R3 R4 X 2 (%) er of 2 3 (%) yield, although identical enantioselectivity was observed for a reaction c,e carried out by mixing the cyano(bisoxazoline) ligand with iron dichloride 1 1 Ph H H H CN 64 74:26 9 (entry 2). An evaluation of solvents and stoichiometric additives39 (see 2c,e FeCl Ph H H H CN 19 74:26 19 Table S3) revealed that high yields and improved selectivities could be 2 obtained for reactions carried out in 1,2-diflurorobenzene as the 3 1 Ph H H H CN 73 79:21 9 solvent and using 1,3,5-trimethoxybenzene (1,3,5-TMB) as a stoichiometric additive (entry 3, Table 1). While using 1,2- 4 4 H 3,5-tBuPh H H CN 36 32:68 9 difluorobenzene improved selectivity, inclusion of 1,3,5-TMB had a 5 5 Mes H H H CN 15 65:35 27 much more significant impact on product yield than selectivity. Next, a variety of aromatic and aliphatic substituted 6 6 H Ph H Ph CN 71 26:74 5 cyanobis(oxazoline) ligands were evaluated (Table 1). Increasing the steric bulk of the aryl group installed on carbon 4 and 4' of the ligand 7 7 Ph H Ph Ph CN 64 65:35 13 led to lower yields and enantioselectivity (entries 4-5). In the case of 8 8 Bn H H H CN 8 61:39 33 iron complex 5, homocoupled product 3 was a major product (entry 5). Adding phenyl substitution to the 4, 4', 5, and 5’ positions of the 9 9 tBu H H H CN 0 N/A 0 cyanobis(oxazoline) ligand resulted in similar yields and enantioselectivities as reactions catalysed by 1 (entries 6-7). Replacing 10 10 iPr H H H CN 16 73:27 20 aromatic with aliphatic substituents on the oxazoline ring led to low 11 11 Ph H H H H 57 76:24 18 conversion of the alkyl halide substrate (entries 8-10). Removing the cyano functionality installed in the backbone of the bis(oxazoline) ligand 12 12 Ph N/A N/A N/A N/A 0 N/A 45 led to lower yields of 2 and higher production of 3 (entry 11).
Load more

Recommended publications
  • WO 2008/096257 Al
    (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (43) International Publication Date PCT (10) International Publication Number 14 August 2008 (14.08.2008) WO 2008/096257 Al (51) International Patent Classification: 500038 (IN). BURIDIPADU, Sunil Kumar [IN/IN]; C07D 239/42 (2006.01) Aurobindo Pharma Limited, Plot No.2, Maitrivihar, Ameerpet, Andhra Pradesh, Hyderabad 500038 (IN). (21) International Application Number: MEENAKSHISUNDERAM, Sivakumaran [IN/IN]; PCT/IB2008/000290 Aurobindo Pharma Limited, Plot No.2, Maitrivihar, Ameerpet, Andhra Pradesh, Hyderabad 500038 (IN). (22) International Filing Date: 4 February 2008 (04.02.2008) (81) Designated States (unless otherwise indicated, for every (25) Filing Language: English kind of national protection available): AE, AG, AL, AM, AO, AT,AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, CA, (26) Publication Language: English CH, CN, CO, CR, CU, CZ, DE, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, (30) Priority Data: IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, KZ, LA, LC, 277/CHE/2007 8 February 2007 (08.02.2007) IN LK, LR, LS, LT, LU, LY, MA, MD, ME, MG, MK, MN, 1121/CHE/2007 29 May 2007 (29.05.2007) IN MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PG, PH, PL, PT, RO, RS, RU, SC, SD, SE, SG, SK, SL, SM, SV, (71) Applicant (for all designated States except US): AU- SY, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ROBINDO PHARMA LIMITED [IN/IN]; Plot No.2, ZA, ZM, ZW Maitrivihar, Ameerpet, Andhra Pradesh, Hyderabad 500038 (IN).
    [Show full text]
  • The Development of Simplified Microreactors for Use in Multi-Step Reaction Sequences
    THE DEVELOPMENT OF SIMPLIFIED MICROREACTORS FOR USE IN MULTI-STEP REACTION SEQUENCES A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Andrew R. Bogdan August 2009 © 2009 Andrew R. Bogdan THE DEVELOPMENT OF SIMPLIFIED MICROREACTORS FOR USE IN MULTI-STEP REACTION SEQUENCES Andrew R. Bogdan, Ph. D. Cornell University 2009 This dissertation describes the development of simplified microreactors to be used in multi-step reaction sequences. Microreactors are a developing technology with numerous benefits and whose modular design permits multi-step reaction sequences to be performed in a continuous flow process. The first chapter discusses the physical properties of microreactors and describes how performing reactions in these miniaturized reactors leads to safer, more efficient and more selective chemical transformations. A brief discussion of multi-step reaction sequences already performed in flow will also be presented. These multi-step reaction sequences, however, rarely rely on catalysis to facilitate chemical transformations. This area therefore has room for great improvement. The next two chapters discuss the development and application of solid-supported catalysts to be used in flow. In the first of these two chapters, two catalysts are immobilized on a solid-support and used in a simplified flow reactor. These reactions proved to be more efficient than similar batch reaction and the catalysts were highly recyclable. The next chapter presents a supported TEMPO catalyst used to oxidize alcohols to carbonyl species. These three catalysts set the foundation for multi-step flow reaction to be potentially performed in the group.
    [Show full text]
  • United States Patent Office Paterated Feb
    3,306,895 United States Patent Office Paterated Feb. 28, 1967 1. 2 3,306,895 The compounds of this invention are obtained by treat HETEROCYCLIC DERVATIVES OF TRPHENYL ment of triphenylethylene derivatives of the type: , ETHYLENES, TRIPHENYLETHANES AND TRI PHENYLETHANOLS Edward McCreery Roberts, George Philip Claxton, and 5 Frances Gertrude Fallon, Cincinnati, Ohio, assignors to Richardson-Merrell Inc., New York, N.Y., a corpo ration of Delaware No Drawing. Filed June 27, 1962, Ser. No. 205,551 10 Claims. (C. 260-240) k This invention relates to a series of novel and useful O where R and R' are as previously defined, with an ap compounds and processes for preparing the same. More propriate organometallic derivative such as cy-picolyl particularly, this invention relates to a series of triphenyl lithium (as in Examples 2 and 5), 3-pyridyl lithium (as ethanes, triphenylethylenes, and triphenylethanols, in in Example 6), or 2-pyridyl lithium (as in Examples 1 which one of the phenyl groups is substituted with a pyri and 4). Such treatment is conveniently carried out by dyl or reduced pyridyl ring which is separated from the mixing the reactants in an inert solvent such as ether, aromatic portion of the molecule by an oxygenated alkyl benzene, toluene, or combinations of such inert solvents fragment of one, two or three carbon atoms. The inven at appropriate temperatures chosen in the range of tion also includes nontoxic, water-soluble addition salts, -60° C. to 80° C. The resulting imine is hydrolyzed to quaternary ammonium derivatives and N-oxide deriva the corresponding ketone without being isolated by being tives of the new compounds.
    [Show full text]
  • Benzopinacolate Promoted Radical Carbon-Carbon Bond Forming
    Bis(trimethylstannyl)benzopinacolate Promoted Radical Carbon-Carbon Bond Forming Reactions and Related Studies Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Franklin Lee Seely Graduate Program in Chemistry The Ohio State University 2010 Dissertation Committee: Robert S. Coleman, Co-Advisor David J. Hart, Co-Advisor T. V. RajanBabu Abstract This research has dealt primarily with the development of novel methods for radical carbon-carbon bond formation. A major focus of this research has been the hydrogen atom free generation of trialkyltin radicals. The bulk of this thesis will deal with the use of bis(trimethylstannyl)benzopinacolate 1 in mediating radical reactions. We have demonstrated that these conditions allow a wide variety of inter and intramolecular free radical addition reactions. We have given evidence that these reactions proceed via a novel non-chain free radical mechanism. ii Dedication This thesis is dedicated to Tracy Lynne Court. You have given me the courage to try again. iii Acknowledgments I would like to sincerely thank Dr. David J. Hart for all his help, the countless hours of work he put in, and for making this possible. I would like to thank Dr. Robert S. Coleman for agreeing to act as my advisor, and all the support and guidance he has given. I would like to than Dr. T. V. RajanBabu for reading my thesis and all his thoughtful suggestions. iv Vita Education 1981-1985 ………………………………………………………..B.S., The University
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,800,658 B2 Brugnara Et Al
    USOO6800658B2 (12) United States Patent (10) Patent No.: US 6,800,658 B2 Brugnara et al. (45) Date of Patent: Oct. 5, 2004 (54) SUBSTITUTED DIPHENYL INDANONE, 5,273,992 A 12/1993 Brugnara et al. ........... 514/398 NDANE AND INDOLE COMPOUNDS AND 5,358,959 A 10/1994 Halperin et al. ...... ... 514/396 ANALOGUES THEREOF USEFUL FOR THE 5,430,062 A 7/1995 Cushman et al. ..... ... 514/646 5,512.563 A * 4/1996 Albright et al. ............ 514/217 TREATMENT OF PREVENTION OF 2002/0128256 A1 * 9/2002 Brugnara et al. ...... 514/212.02 DISEASES CHARACTERIZED BY ABNORMAL CELL PROLIFERATION FOREIGN PATENT DOCUMENTS (75) Inventors: Carlo Brugnara, Newton Highlands, DE 37O6427 9/1988 DE 1OOO4654 8/2001 MA (US); Jose Halperin, Brookline, EP O323 740 A2 7/1989 MA (US); Rudolf Fluckiger, Brookline, EP 483632 5/1992 MA (US); Emile M. Bellott, Jr., EP O 583 665 A2 2/1994 Beverly, MA (US); Richard John EP O 636 608 A1 2/1995 Lombardy, Littleton, MA (US); John JP OS 58894 3/1993 J. Clifford, Arlington, MA (US); JP OSOSO771 3/1993 Ying-Duo Gao, Meshanie Station, NJ WO WO 89/08096 9/1989 (US); Reem M. Haidar, Woburn, MA WO WO95/26720 10/1995 (US); Eugene W. Kelleher, Somerville, WO WO 96/08240 3/1996 MA (US); Adel M. Moussa, WO WO 96/08242 3/1996 Burlington, MA (US); Yesh P. WO WO 96/36631 11/1996 Sachdeva, Concord, MA (US); WO WO 99/26624 6/1999 Minghua Sun, Cambridge, MA (US); WO WO O2/32465 4/2002 Heather N.
    [Show full text]
  • Iron-Catalysed Enantioconvergent Suzuki-Miyaura Cross-Coupling to Afford Enantioenriched 1,1-Diarylalkanes
    Electronic Supplementary Material (ESI) for Chemical Communications. This journal is © The Royal Society of Chemistry 2020 Iron-Catalysed Enantioconvergent Suzuki-Miyaura Cross-Coupling to Afford Enantioenriched 1,1-Diarylalkanes Chet C. Tyrol, Nang S. Yone, Connor F. Gallin, Jeffery A. Byers* Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States General Considerations .................................................................................................. 1 Synthetic Procedures ...................................................................................................... 3 Figure S1. Synthesis of cyano-bis(oxazoline) ligands and iron complexes ..................... 3 Synthesis of Diarylalkanes ............................................................................................. 18 Preparation of arylboronic pinacol esters ..................................................................... 30 Preparation of benzylic halides ...................................................................................... 31 Figure S2. Resubjection of enantiomerically-enriched product ......................................... 36 Table S1. Solvent and additive screen .............................................................................. 37 Table S2. Bis(oxazoline) ligand screen ............................................................................. 38 Table S3. Effect of catalyst loading ..................................................................................
    [Show full text]
  • ME Manning Et Al., Chem. Abstract 94.102538, 1981
    USOO6992O79B2 (12) United States Patent (10) Patent No.: US 6,992,079 B2 Brugnara et al. (45) Date of Patent: *Jan. 31, 2006 (54) SUBSTITUTED 4,006,023 A 2/1977 McLaughlin et al. ....... 96/90 R 11-PHENYL-DBENZAZEPINE COMPOUNDS 4,806,685 A 2/1989 Abraham et al. ........... 563/324 USEFUL FOR THE TREATMENT OR 5,273,992 A 12/1993 Brugnara et al. ..... ... 514/398 5,358,959 A 10/1994 Halperin et al. ...... ... 514/396 ERR2E, RMAL cell 5,430,062. A 7/1995 Cushman et al. ........... 514/646 5,512.563 A * 4/1996 Albright et al. ............ 514/217 PROLIFERATION 6,063,921 A 5/2000 Moussa et al. (75) Inventors: Carlo Brugnara, Newton Highlands, 6,291,4496,201,120 B1 9/20013/2001 Ms t alal. MA (US); Jose Halperin, Brookline, 6,534,497 B1 * 3/2003 Brugnara et al. ........... 514/217 MA (US); Rudolf Fluckiger, Brookline, 2001/0007030 A1 7/2001 Moussa et al. MA (US); Emile M. Bellott, Jr., Beverly, MA (US); Richard John FOREIGN PATENT DOCUMENTS Lombardy, Littleton, MA (US); John EP O 323 740 A2 7/1989 J. Clifford, Arlington, MA (US); EP O 583 665 A2 2/1994 Ying-Duo Gao, Edison, NJ (US); Reem EP O 636 608 A1 2/1995 M. Haidar, Woburn, MA (US); Eugene JP OS 58894 3/1993 W. Kelleher, Medford, MA (US); Adel WO WO95/26720 10/1995 M. Moussa, Burlington, MA (US); WO WO 96/08240 3/1996 Yesh P. Sachdeva, Concord, MA (US); W W 't f1. Minghua Sun, Libertyville, IL (US); Heather N.
    [Show full text]
  • Chemfiles 9.3 Cover.Indd 1 6/18/2009 7:49:52 AM Vol
    Vol. 9, No. 3 Chiral Building Blocks Features include: A–Z Product Listings Heterocyclic Building Blocks Organic Building Blocks (S)-(–)-Glycidol: chiral epoxide building block used in synthesis of many pharmaceuticals and natural products 70978 ChemFiles 9.3 cover.indd 1 6/18/2009 7:49:52 AM Vol. 9 No. 3 Introduction Asymmetric synthesis remains a challenge to synthetic chemists as Aldrich Chemical Co., Inc. the demand for enantiomerically pure compounds continues to Sigma-Aldrich Corporation increase. Whether the building blocks are used in the development 6000 N. Teutonia Ave. of new and exciting chiral auxiliaries, ligands, or for obtaining Milwaukee, WI 53209, USA advanced and enantiomerically enriched druglike molecules, research scientists continually need access to a vast array of novel chiral building blocks and architectures to achieve success. To Place Orders In this edition of ChemFiles, we have endeavored to provide a comprehensive listing of over 1000 chiral building blocks. Within Telephone 800-325-3010 (USA) each section of this issue, products are listed by increasing FAX 800-325-5052 (USA) carbon content. Introduction Mark Redlich Sigma-Aldrich is lists over 5000 chiral products for the successful Product Manager Customer & Technical Services construction of complex asymmetric architectures—for a complete listing of products related to chiral chemistry and asymmetric synthesis, please visit us at Customer Inquiries 800-325-3010 sigma-aldrich.com/chiral. If you are unable to find a product for Technical Service 800-231-8327 your research, “Please Bother Us” at [email protected] or contact your local SAFC® 800-244-1173 Sigma-Aldrich office.
    [Show full text]
  • Adsorption Behavior of the Primary, Secondary and Tertiary Alkyl, Allyl and Aryl Alcohols Over Nanoscale (1 0 0) Surface of Γ-Alumina
    Adsorption Behavior of the Primary, Secondary and Tertiary Alkyl, Allyl and Aryl Alcohols Over Nanoscale (1 0 0) Surface of γ-Alumina Mehdi Zamani1,2*, Hossein A. Dabbagh2* 1) Department of Chemistry, Malek-ashtar University of Technology, Shahin-shahr P.O. Box 83145/115, Islamic Republic of Iran 2) Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran Abstract In this study, the adsorption behavior of the primary, secondary and tertiary alcohols over nanoscale (1 0 0) surface of defect spinel γ-alumina was investigated with the aid of density functional theory (DFT) at BLYP/DNP level of calculation. The influence of different substituents including alkyl, cycloalkyl, allyl and aryl were analyzed for free and adsorbed alcohols to shed light the adsorption selectivity of these compounds over γ-alumina surface. These results indicate that more branches at position of alcohol favor the adsorption, while a decrease in adsorption energy is achieved for the alcohols containing the substituents at the β position. The tertiary alcohols are adsorbed over the surface stronger than secondary and primary alcohols. Alcohols with larger alkyl chains have greater adsorption energies. Also the aryl alcohols are adsorbed over the surface better than the alkyl and allyl moieties. Keywords: Nanoscale surface of γ-Alumina; Alcohol; Molecular adsorption; DFT © 2014 Published by Journal of Nanoanalysis. 1. Introduction Alumina is well known catalyst by both acidic and basic properties. In recent years, many experimental and theoretical works have studied the structure, reactivity and selectivity of γ-alumina especially at nanoscale (1-23). Theoretical investigations of the adsorption on γ-alumina have focused mostly on Lewis acidity of the surface (1-4), and the reactivity with water (5-11), hydrogen sulfide (5,10,12), carbon monoxide (5,10,13), ammonia (6), pyridine (4,6), hydrogen chloride (7), alkenes (14,15), alkanes (16), alcohols (17-23) and ethers (23).
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8,349,977 B2 Koenig Et Al
    US008349977B2 (12) United States Patent (10) Patent No.: US 8,349,977 B2 Koenig et al. (45) Date of Patent: Jan. 8, 2013 (54) PROCESS FOR PREPARING W. W338 A .289 SETITY ISOBUTENE HOMO- OR WO WO 2010, 139684 A1 12/2010 OTHER PUBLICATIONS (75) Inventors: Hannah Maria Koenig, Mannheim (DE); Klaus Muellbach, Gruenstadt Edward C. Leonard. “High Polymers'. Wiley-Interscience, A Divi (DE); Matthias Kiefer, Ludwigshafen sion of John Wiley & Sons, Inc., vol. XXIV. (part 2), 1971, 1 front (DE); Sergei V. Kostjuk, Minsk (BY); page, pp. 713-733. 66/ - - - - - Irina Vasilenko, Minsk (BY): James D. Burrington, et al., Cationic polymerization using s s heteropolyacid salt catalysts'. Topics in Catalysis, vol. 23, Nos. 1-4. Alexander Frolov, Svisloch (BY) Aug. 2003, pp. 175-181. Sergei V. Kostjuk, et al., “Novel Initiating system based on AlCl (73) Assignee: BASFSE, Ludwigshafen (DE) etherate for quasiliving cationic polymerization of styrene'. Polymer Bulletin, vol. 52, 2004, pp. 227-234. (*) Notice: Subject to any disclaimer, the term of this Sergei V. Kostjuk, et al., “Cationic Polymerization of Styrene in patent is extended or adjusted under 35 Solution and Aqueous Suspension Using B(C6F5) as a Water-Toler U.S.C. 154(b) by 0 days. ant Lewis Acid', Macromolecules, vol.39, No. 9, Apr. 8, 2006, pp. 3110-3113. (21) Appl. No.: 13/029,413 U.S. Appl. No. 13/126,857, filed Apr. 29, 2011, Hildebrandt, et al. U.S. Appl. No. 13/305,132, filed Nov. 28, 2011, Koenig, et al. (22) Filed: Feb. 17, 2011 U.S. Appl. No. 13/305,283, filed Nov.
    [Show full text]
  • Spectra Library Index SDBS Library
    S p e c t r a L i b r a r y I n d e x SDBS Library KBr ライブラリー名：スタンダードライブラリーKBr 商品番号：40001-40 株式会社 エス・ティ・ジャパン 〒103-0014 東京都中央区日本橋蛎殻町 1-14-10 Tel: 03-3666-2561 Fax:03-3666-2658 http://www.stjapan.co.jp 1 【販売代理店】（株）テクノサイエンス Tel：043-206-0155Fax：043-206-0188 http://www.techno-lab-co.jp/ (((3,4-DIHYDROXY-9,10-DIOXO-9,10-DIHYDRO-2-ANTHRYL)METHYL)IMINO)DIACETIC ACID (((N-BENZYLOXYCARBONYL-L-PHENYLALANYL)-O-ACETYL-L-THREONYL)-L-PROLYL-L-PHENYLALANYL)-N(OMEGA)-NITRO-L-ARGININE 4-NITROBENZYL ESTER ((1,2-DIETHYLETHYLENE)BIS(P-PHENYLENE))DIACETATE ((1-BENZOTRIAZOLYL)OXY)TRIS(DIMETHYLAMINO)PHOSPHONIUM HEXAFLUOROPHOSPHATE ((2-(3-BENZYLSULFONYL-4-METHYLCYCLOHEXYL)PROPYL)SULFONYLMETHYL)BENZENE ((2,4,6-TRIOXOHEXAHYDRO-5-PYRIMIDINYL)IMINO)DIACETIC ACID ((2-BENZOTHIAZOLYL)AMINOMETHYLENE)MALONONITRILE ((2-CARBOXYETHYL)IMINO)DIACETIC ACID ((2-CYANOETHYLAMINO)(3-INDOLYL)METHYLENE)MALONONITRILE ((2-HYDROXYETHYL)IMINO)DIACETIC ACID ((2-HYDROXYETHYLAMINO)(3-INDOLYL)METHYLENE)MALONONITRILE ((2-NITROBENZYL)IMINO)DIACETIC ACID ((2-OXOPROPYL)IMINO)DIACETIC ACID ((2-PYRIDYLAMINO)METHYLENE)MALONONITRILE ((2-QUINOLINYL)AMINOMETHYLENE)MALONONITRILE ((2-SULFOETHYL)IMINO)DIACETIC ACID ((2-THIAZOLYLAMINO)METHYLENE)MALONONITRILE ((3-(1-BROMO-1-METHYLETHYL)-7-OXO-1,3,5-CYCLOHEPTATRIEN-1-YL)OXY)DIFLUOROBORANE ((3-INDOLYL)(1-PYRROLIDINYL)METHYLENE)MALONONITRILE ((3-INDOLYL)(METHYLTHIO)METHYLENE)MALONONITRILE ((3-INDOLYL)MORPHOLINOMETHYLENE)MALONONITRILE ((3-INDOLYL)PIPERIDINOMETHYLENE)MALONONITRILE ((3-METHYL-2-PYRIDYLAMINO)METHYLENE)MALONONITRILE ((4-METHYL-2-PYRIDYLAMINO)METHYLENE)MALONONITRILE
    [Show full text]
  • Part I Asymmetric Reduction of Ketones with the Grignard Reagent from R-1
    University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Spring 1970 PART I ASYMMETRIC REDUCTION OF KETONES WITH THE GRIGNARD REAGENT FROM R-1-BROMO-2-PHENYLETHANE-1,1,2-DEUTERIUM(3) PART II ELECTROPHILICALLYASSISTED NUCLEOPHILIC OPENING OF OPTICALLY ACTIVE STYRENE-OXIDE JOSEPH EDWARD TOMASZEWSKI Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation TOMASZEWSKI, JOSEPH EDWARD, "PART I ASYMMETRIC REDUCTION OF KETONES WITH THE GRIGNARD REAGENT FROM R-1-BROMO-2-PHENYLETHANE-1,1,2-DEUTERIUM(3) PART II ELECTROPHILICALLYASSISTED NUCLEOPHILIC OPENING OF OPTICALLY ACTIVE STYRENE-OXIDE" (1970). Doctoral Dissertations. 925. https://scholars.unh.edu/dissertation/925 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. PART I. ASYMMETRIC REDUCTION OF KETONES WITH THE GRIGNARD REAGENT FROM R-1 -BROMO- 2 -PHENYLETHANE-1,1,2-d s PART II. ELECTROPHILICALLY ASSISTED NUCLEOPHILIC OPENING OF OPTICALLY ACTIVE STYRENE OXIDE by JOSEPH EDWARD TOMASZEWSKI B. S., University of Scranton, 1965 A THESIS Submitted to the University of New Hampshire In Partial Fulfillment of The Requirements for the Degree of Doctor of Philosophy Graduate School Department of Chemistry March, 1970 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. This thesis has been examined and approved. ?s D. Morrison, Research Director rbciate Professor of Chemistry Rob'er't E .
    [Show full text]