Chem. Rev. 1994, 94, 2483-2547 2483 Catalytic Asymmetric Dihydroxylation Hartmuth C. Kolb,t Michael S. VanNieuwenhze,* and K. Barry Sharpless* Department of Chemistry, The Scripps Research Institute, 10666 North Torfey Pines Road, La Jolla, California 92037 Received Ju/y 28, 1994 (Revised Manuscript Received September 14, 1994) Contents 3.1.4. Differentiation of the Hydroxyl Groups by 2524 Selective, Intramolecular Trapping 1. Introduction and General Principles 2483 3.1.5. Miscellaneous Transformations 2525 2. Enantioselective Preparation of Chiral 1,2-Diols 2489 3.2. Preparation of Chiral Building Blocks 2527 from Olefins 3.2.1. Electrophilic Building Blocks 2527 2.1. Preparation of Ligands, Choice of Ligand, 2489 Scope, and Limitations 3.2.2. Chiral Diol and Polyol Building Blocks 2529 2.1.1. Preparation of the Ligands 2490 3.2.3. Chiral Monohydroxy Compounds Derived 2529 from Diols 2.1 -2. Ligand Choice and Enantioselectivity Data 2490 3.2.4. 5- and 6-Membered Heterocycles 2530 2.1.3. Limitations 2491 3.3. Preparation of Chiral Auxiliaries for Other 2530 2.2. Reaction Conditions 2493 Asymmetric Transformations 2.2.1. Asymmetric Dihydroxylation of the 2493 3.3.1. Preparation of 2530 “Standard Substrates” (1 R,2S)-trans-2-phenylcyclohexanol 2.2.2. Asymmetric Dihydroxylation of 2496 3.3.2. Optically Pure Hydrobenzoin (Stilbenediol) 2531 Tetrasubstituted Olefins, Including Enol and Derivatives Ethers 4. Recent Applications: A Case Study 2536 2.2.3. Asymmetric Dihydroxylation of 2496 Electron-Deficient Olefins 5. Conclusion 2538 2.2.4. Chemoselectivity in the AD of Olefins 2497 6. References and Footnotes 2542 Containing Sulfur 2.3. Double Diastereoselection and Kinetic 2497 1. Introduction and General Principles Resolution 2.3.1. Double Diastereoselection 2497 During the last decade a number of powerful 2.3.2. Kinetic Resolution 2502 asymmetric reactions have emerged as a result of the growing need to develop efficient and practical syn- 2.4. Asymmetric Dihydroxylation of 2503 Polyunsaturated Substrates theses of biologically active compounds. Catalytic asymmetric reactions provide an especially practical 2.4.1. Formation of Polyols from Conjugated 2504 and Nonconjugated Polyenes entry into the chiral world due to their economical use of asymmetry inducing agents.l A number of 2.4.2. Selective Mono-dihydroxylation of 2506 Polyenes processes have gained wide acceptance, and some of them are even used on an industrial scale. Among 2.4.3. Asymmetric Dihydroxylation of Cyclic 2508 Polyenes the most prominent examples are the “Monsanto Process” for the asymmetric hydrogenation of dehy- 2.4.4. Asymmetric Dihydroxylation of Enynes 2509 droamino acids2 and the enantioselective isomeriza- 2.5. Influence of Acidic Hydrogens in the 2510 tion of allylic amine^,^ used in the “TakasagoProcess’’ Substrate on Rates, Chemoselectivity, and Stereoselectivity for the manufacture of (-)-menthol. The asymmetric 2.5.1. Influence on Regioselectivity epoxidation of unfunctionalized olefins, catalyzed by 251 1 manganese-salen complexes, also has considerable 2.5.2. Influence on Stereoselectivity 251 2 p~tential.~Our own efforts in the field of asymmetric 2.5.3. Influence on Rates 251 3 oxidation of olefins5have led to two useful reactions, 2.5.4. Summary 251 3 the asymmetric epoxidation6 (AE)and the osmium- 3. Synthetic Applications for 1,2-Diols 251 3 catalyzed asymmetric dihydr~xylation~(AD). While 3.1. Methods for the Differentiation of the 2514 the former reaction requires the presence of a direct- Hydroxyl Groups of a Diol ing functional group in the substrate (allylic alcohols), 3.1.1. Selective Arenesulfonylation 251 4 the dihydroxylation process is much less limited in 3.1 -2. Cyclic Sulfites and Sulfates as 251 5 the choice of substrate, since it does not need any Epoxide-like Synthons directing functional group to be present. Strikingly, 3.1.3. Conversion of Diols into Halohydrin 251 8 both processes crucially depend on the ligand ac- Esters and Epoxides celeration effect (LAE),6b-dJ?which ensures that the reaction is funneled through a pathway involving the * The author to whom corres ondence should be addressed. Fax chiral catalyst. The principle of ligand acceleration no.: 619-554-6406. E-mail achress: [email protected] s.edu. is illustrated in Scheme 1 for the AD reaction. t Current address: CIBA-GEIGY, Zentrale Forschungslaiorato- In his pioneering work on the stoichiometric reac- rien, R-1060.3.10, CH-4002 Basel, Switzerland. 1: Current address: Lilly Research Laboratories, Eli Lilly and Co., tion of os04 with olefins, Criegee showed that pyri- Lilly Corporate Center, Indianapolis, IN 46260. dine accelerates the reaction con~iderably.~However, 0009-2665/94/0794-2483$14.00/00 1994 American Chemical Society 2484 Chemical Reviews, 1994, Vol. 94, No. 8 Kolb et al. I HarbnuM C. Kolb did his undergraduate studies at Me University of K. rry Sharpless (b. 1941), W. M. Kwk )lessor of Chemistry at the Hannover, Germany, where he obtained his diploma in 1989. For his Scripps Research Institute. was deflected hom pre-med to chemishy alter Ph.D. he moved to London to work with S. V. Ley on the synthesis of the doing research in Thomas A. Spencer's laboratory at Dartmoulh College. limonoid azadirachtin. Two years later he joined K. B. Sharpless's Following a Stanford Ph.D. with E. E. van Tamelen and postdoctoral years research group at Scripps as a postdoctoral fellow. Initial research on wiih James P. Collman at Stanford and Konrad Bloch at HaNard, synthetic applications of the asymmetric dihydrovlation was followed by Sharpless joined the M.I.T. faculty. He taught there, as well as at Stanford studies on the mechanism of the same reaction. In November 1993, he in the 197oS, until moving to Scripps in 1990. Finding new metalcatalyzed joined the central research laboratories 01 ClBA in Basle. where he is transformations of use in organic synthesis is the main goal of his research. currently working in the carbohydrate section. His research interests include organic synthesis, molecular recognition and molecular modeling. Scheme 1. The Osmylation of Olefins Initial efforts by Sharpless and Hentges to induce enantioselectivity in the osmylation with chiral py- Michael S. VanNieuwenhze (b. 1962) received his undergraduate education ridine derivatives failed due to the low affinity of at Kalamazoo (MI) College. He then spent two years as an organic these ligands for 0~04.'~~It was found that the chemist in the Parke-Davis Pharmaceutical Research Division of Wamer- binding constant of a ligand is extremely sensitive Lambert, Inc. After an appointment in the laboratory of Professor Samuel to the steric hindrance near the reacting center. Danishefsky at Yale University, Michael obtained the Ph.D. degree in Consequently, quinuclidine derivatives were used 1992 under the direction of Professor William R. Roush at Indiana instead of pyridines for further investigations due to University. Upon completion of his graduate study, he joined the research group of Professor K. Barry Sharpless at the Scripps Research Institute their intrinsically higher affinity for OSO~.'~This as a National Institutes of Health postdoctoral lellow. He is presently logic proved correct, and in 1979 it allowed Hentges employed by Eli Lilly and Company. His research interests include to isolate diols with moderate to good enantiomeric asymmetric synthesis, carbohydrate chemistry, and metalmediated excesses using acetate esters of cinchona alkaloids asymmetric transformations. as chiral ligand@ (Figure la, R = Ac). cost considerations make the stoichiometric osmyla- Apart from the cinchona alkaloid catalyzed asym- tion uneconomical. Not surprisingly, catalytic vari- metric dihydroxylation, there are very few other ants of the reaction, which employ relatively inex- catalytic systems. Recently, Hirama et al. employed pensive reagents for the reoxidation of the osmium(VI) a monodentate 1,4-diazabicyclo[2.2.2loctane (DAB glycolate products, greatly enhance its synthetic CO) derivative (Figure lb) to effect dihydroxylation utility.'O Inorganic cooxidants, such as sodium or of olefins under catalytic conditions16' (1mol % 0~04, potassium chlorate" or hydrogen peroxide,I2were the 5 mol % ligand). Unfortunately, the enantiomeric first to be introduced, but in some cases these excesses are far from satisfactory (541% ee) even reagents lead to diminished yields due to over- with stilbene. Better results were achieved by Mu- oxidation. Much better results are obtained with rahashi and co-workers16"who employed chiral isox- alkaline tert-butyl hydroperoxide, introduced by Sharp- azolidines (Figure 1)to effect the same transforma- less and Akashi,13 or N-methylmorpholine N-oxide14 tion in up to 73% ee. (Upjohn Process). Recently, Minato, Yamamoto, and A number of recent methods employ chiral diamine Tsuji demonstrated that &Fe(CN)c in the presence ligands for the asymmetric osmylation of 01efins~J~~-" of KzC03 provides a powerful system for the osmium- (Figure le). Good results have been achieved very catalyzed dihydroxylation of 01efins.l~ recently by Hanessian et al. with a simple, trans-1,2- Catalytic Asymmetric Dihydroxylation Chemical Reviews, 1994, Vol. 94, No. 8 2485 (a) Cinchona Alkaloid Ligands for AD under Catalytic Condition~~~~J~J~J~ Me0 Dihydroquinidine (R = H) j Dihydroquinine (R = H) DHQD DHQ (b) Recent Monodentate Ligands for AD under Catalytic Conditions R = ’BuPh2Si-OR Hirama et al. Murahashi et a1.I6” (c) Chiral Diamine Ligands for AD under Stoichiometric Conditions P-4- Snyder et a1.16m Hanessian et al. 16b Corey et aZ.16~ p’?. ph, Ar L\SN*Ar Pr1-N n h WN-NWN--’Pr Ar = Ph, 3,5-~ylyl ’,,ar Tomioka et al. 16d-g Fuji et I I R R R = neohexyl Nap = a-naphthyl Hirama et al. 16Jqk Narasaka et ~1.l~~ Figure 1. Some ligands for asymmetric dihydroxylation.16 Only monodentate ligands allow a reaction under catalytic conditions. Note that DHQD and DHQ are diastereomers and not enantiomers due to the presence of the ethyl group at C3. Although ligands derived from these two “pseudoenantiomeric”alkaloids lead to diols of opposite configuration, the ee’s are usually not identical.