Gacl3-Promoted Addition Reactions of Carbon Nucleophiles to Alkyne Yoshiyuki Kido, Mieko Arisawa, and Masahiko Yamaguchi* Depart

GaCl3-Promoted Addition Reactions of Carbon Nucleophiles to Alkyne

YoshiyukiKido, Mieko Arisawa, and Masahiko Yamaguchi*

Departmentof OrganicChemistry, Graduate School of Pharmaceutical Sciences, Tohoku University,

Received June 6, 2000

Abstract : GaCl3 promotes addition reactions of carbon nucleophiles to a C-C triple bond. Interaction of

alkyne with GaCl3 generates a highly reactive electrophile, which aromatic hydrocarbon attacks to give an alkenylated arene. Silylethyne reacts predominantly at the p-position of toluene, while disilylated 1, 3-butadiyne exhibits ƒÍ-selectivity. The behavior of a silylated 1, 2-propadiene is intermediate between that of the silylethyne and the disilylated 1, 3-butadiyne. In the presence of GaCl3, electrophilic trimerization of silylethyne takes place to give a conjugated hexatriene. In this reaction, silylethyne attacks the GaCl3-activated C-C triple bond. Carbometalation is another interesting addition reaction of an organogallium com-

pound to alkyne. Alkynyldichlorogallium dimerizes in hydrocarbon solvents to give 1,1-dimetallo-1-buten- 3-yne. In the presence of GaCl3, silyl enol ether is ethenylated at the ƒ¿-carbon atom with trimethylsilylethyne. Treatment of lithium phenoxide with silylethyne in the presence of GaCl3 gives ƒÍ-(ƒÀ-silylethenyl)

phenol. These reactions involve carbogallation of alkynylgallium, gallium enolate, or gallium phenoxide.

1. Introduction 2. Nucleophilic Addition Reactions to Alkyne Activated by

GaCl3 Gallium is a group 13 element, and sits just below aluminum in the periodic table. Its derivatives have rarely been 2.1 Aromatic Alkenylation Reactions used in organic synthesis,1,2 although aluminum derivatives GaCl3 activates a C-C triple bond electrophilically and are quite popular. Attempts to utilize organogallium com- promotes nucleophilic attack of ƒÎ-compounds such as pounds generally revealed that they are less reactive than arene4,5 or alkyne.6 GaCl3-activated silylethyne reacts with organoaluminum compounds. The reduced reactivity has an aromatic hydrocarbon or 1,2,3-trimethoxybenzene.4,5 been attributed to the less polarized nature of the Ga-C Other unsaturated compounds, 1, 4-disilyl-1, 3-butadiyne7 bond compared to the Al-C bond, based on the relative elec- and 1,2-propadiene,8 when treated with GaCl3, are also tronegativity of Ga (1.8) and Al (1.5).3 We found that GaCl3 attacked by an aromatic hydrocarbon. promotes addition reactions of carbon nucleophiles to C-C The structure of the complex derived from the unsaturated triple bond, and that the reactions proceed much more effec- compound and GaCl3 can be studied in some cases by tively than with AlCl3. The reactions take place either via i) low-temperature NMR (Figure 2). Complexation of GaCl3 cicctrophilic activation of alkyne by formation of a ƒÎ-com- and silylethyne at -78 •Ž results in a low-field chemical plex with GaCl3, or ii) carbogallation. Described here are shifts of the acetylenic proton and carbons.5 Calculations several such examples. GaCl3 of high purity is commercially indicate a ƒÎ-complex structure rather than an open cationic available at modest price. GaCl3 is soluble in various organic structure. Treatment of 1-triethylsily1-1,2-propadiene with solvents even in hydrocarbons, and can conveniently be han- GaCl3 at -85 •Ž results in a low-field shift of 1-H by 1H-NMR dled as stock solutions. We prefer to use methylcyclohexane , while the shift was subtle at 3-H. 2-C shifts to as the solvent, since its melting point is much lower than that low field by 13C-NMR, and 3-C slightly to high field.8 It is of cyclohexane. likely that GaCl3 interacts with the double bond of the allene

adjacent to the silyl group. 1. Electrophilic activation of it-electron system

Figure 2 2. Carbogallation

GaCl3 promotes aromatic ƒÀ-silylethenylation (Scheme 1).4,5 Treatment of trimethylsilylethyne (1) and aromatic hydrocarbon with GaCl3 at -78 •Ž followed by methyllithium or THE gives (E)-(ƒÀ-trimethylsilylethenyl)arene. Since the silyl

Figure 1 group can be removed, this is a formal aromatic ethenylation.9

1030 ( 6 ) J. Synth . Org . Chem . , Jpn . Use of GaC13 or GaBr3 is critical; other Lewis acids (A1C13, introduced from the organometallic reagent at the 5-position. A1Br3, InCl3, SnC14, SbC15, SbF5), protic acids (CF3S03H Two carbon-carbon bonds, one electrophilically and the and HC1), or heterogeneous acids (Na-Montmorillonite, other nucleophilically, are formed on a benzene ring. The Sn-Montmorillonite, Montmorillonite K 10) are not effective. first step of the ipso-substitution is the reaction of the elec- It should be emphasized that the ,8-silylethenylation is pro- trophilic gallium complex with 1, 2, 3-trimethoxybenzene at moted by GaC13 but not by A1C13. 2-position by a similar mechanism described in Scheme 2.

Scheme 1 Scheme 3

The reaction proceeds via several organogallium intermedi- ates (Scheme 2). The conventional aromatic alkenylation 1,4-Ditrimethylsily1-1,3-butadiyne 5 can also be used for reactions were generally conducted at 0 •Ž to room tempera- the alkenylation (Scheme 4).7 Arene and 5 are reacted with ture using aromatic compounds in large excess.10 In contrast, GaC13 at -90 to -100 •Ž for 1-2 h. Addition of THE and this ƒÀ-silylethenylation proceeds at -78 •Ž within several an aqueous workup give (Z)-1,4-di (trimethylsilyl)-2- hours employing close to an equimolar amount of arene and aryl- 1-buten-3-yne 6 and 4-trimethylsily1-2-ary1-1- silylethyne. Apparently, a much more reactive electrophilic buten-3-yne 7.5 The olefinic trimethylsilyl group of 6 can be reagent is generated here. We ascribe it to the formation of a removed, producing 7, by careful treatment with CF3COOH.

π-complex derived from silylethyne and GaCl3. The next Scheme 4 step in the ƒÀ-silylethenylation is the nucleophilic attack of an aromatic hydrocarbon to the complex at the ƒÀ-carbon atom.

The regioselectivity may be explained by the ƒÀ-cation stabi- 5 lizing effect of the trialkylsilyl group.11 Addition of methyllithium or THF to the resulted arenium cation 2 provides vinylgallium intermediate 3 or 4, respectively. Methyllithium or THF is essential for the aromatization of the arenium cation 2 by deprotonation. Usually, polyalkenylation does not take place in this reaction, which may be due to the formation of such stable arenium cation in the reaction mixture.

These vinylgalliums 3 and 4 can be detected spectroscopical- 6 7 ly, and workup with D20 gives the corresponding deuterated product.

Scheme 2

2 GaC13 activates not only the C-C triple bond but also the doublc bond of allene.8 When arene and 1-tilethylsily1-1,2- propadiene (8) are reacted with GaC13, (E)-1-sily1-1-

3 propen-2-ylated arene is obtained (Scheme 5). The C-C bond formation takes place exclusively at the 2-position of 8.

β-Cation stabilization by the silicon substituent probably plays an important role.11 This alkenylation is likely to pro- 4 ceed via an organogallium electrophile generated from 8 and GaC13 (Figure 2).

Scheme 5 Unusual ipso-substitution reaction takes place with 1,2, 3-trimethoxybenzene (Scheme 3).5 When an equimolar amount of 1,2,3-trimethoxybenzene is treated with dimethylphenylsilylethyne in the presence of GaC13 at -90 8 ℃, which is fbllowed by methyllithium or alkylmagnesium bromide and acetic acid, a silylethenylated product was Alkylallene shows different behavior from that of 8. 1,2- obtained. The substitution of the 2-methoxy group with the Undecadiene (9) is reacted with p-xylene at -78 •Ž in the

silylethenyl group occurs. In addition, an alkyl group is presence of GaC13, which is followed by methylmagnesium

Vo1.58 No.11 2000 ( 7 ) 1031

bromide and D20. An isomeric mixture of allylated product at the p-position predominantly. In contrast, the reaction 10 (X=D) and alkenylated product (E)-11 is obtained with with 5 occurs exclusively at the o-position. The electrophile the former predominating (Scheme 6). The alkyl substituent derived from 5 shows unusually high tendency to alkenylate of 9 appears to stabilize the allyl cation rather than the vinyl the o-position of alkyl substituents : Ethylbenzene and iso- cation. While 10 is deuterated, (E)-11 is not. The com- propylbenzene also predominantly react at the o-position pound 10 (X-=D), therefore, should be formed from the cor- (Scheme 4). t-Butylbenzene gives a m-isomer as the major responding vinylgallium 10 (X= GaMe2) by a similar mecha- product. Development of the o-selective reaction in the elec- nism to the reaction of 1 (Scheme 2). trophilic aromatic substitution is an issue still not solved.12 Several benzene derivatives possessing heteroatom functional- Scheme 6 ities are known to exhibit such o-selectivity, which are ascribed to the interaction between the electrophile and the substituent.13 The o-selectivity in the GaC13-promoted reaction of alkylbenzenes, which lack such functionality, therefore, is interesting.14 The structure of the electrophile precur- 9 sor is also very important for the o-selectivity (Figure 3). Disilylated octatetrayne 12 exhibits p-selectivity. The behavior of silyl-1, 2-propadiene 8 is intermediate between 1 and 5. This series probably reflects some property of the complexes derived from GaC13 and the unsaturated compounds. Polysubstituted benzenes also show tendency to react with 10 (E)-11 1 at the less hindered sites and with 5 at the adjacent posi- tions of the alkyl substituents (Figure 4). The orientation of the reaction using 8 is again intermediate. o-Xylene is exclusively alkenylated at the 4-position with 1 and the 3-position The organogallium electrophile generated by the interac- with 5; 1,2,3,4-tetrahydronaphthalene predominantly reacts tion of an unsaturated compound and GaC13 shows several interesting properties in the aromatic alkenylation. The electrophile is extremely reactive compared to the conventional alkenylating reagents. In addition, the products often are gallated at the olefin moiety, which can be used for further functional manipulations. 2.2 Orientation Various aspects of these aromatic substitution reactions promoted by GaC13 are consistent with the electrophilic mechanisms. For example, benzene and chlorobenzene are less reactive compared to alkylsubstituted benzenes. The orientation also supports this mechanism. However, interesting differences are observed in the reaction of silylethyne 14,5 and disilylated 1, 3—butadiyne 57 (Figure 3)_ Toluene reacts with 1

Figure 3 Figure 4

1032 ( 8 ) J. Synth. Org. Chem., Jpn.

at the 6-position with 1 and the 5-position with 5; while mation of the conjugated triene involves two C(sp2)-C(sp2) m-xylene reacts with 1 at the 4-position exclusively, reaction bond formations and organometal alkylation at the terminal takes place substantially at the 2-position with 5. Detritia- sp2-carbon. tion experiments indicate that the p-position of toluene is Scheme 7 about twice as reactive as the o-position.15 Similarly, the

4-position of o-xylene, the 6-position of 1, 2, 3, 4-tetrahydronaphthalene, and the 4-position of m-xylene are more reactive than the others.15 The detritiation is considered to reflect the reactivity of the aromatic sites excluding the steric effects. The orientation of the ƒÀ-silylethenylation using 1, The mechanism of the trimerization is shown in Scheme 8. therefore, can be understood by taking into account the elec- The reaction is initiated by the formation of a GaC13-alkyne tronic and the steric effects. The orientation of the reaction complex. Electrophilic head-to-tail trimerization then leads using 5, however, is peculiar : Reaction at the less reactive trienyl cation 13, which is alkylated with methylmagnesium and more hindered site predominates. The following exam- bromide to give vinylgallium. Finally, the product is ples also show the anomalous orientation of this reaction. obtained by protodegallation. The terminal carbon atom of Much higher selectivity to react at the 4-position of 13 attacked by an organometal reagent as well as the proton

1,2,3-trimethylbenzene is observed with 5 than with 1. attached shows characteristic low-field chemical shifts, 13C- 1-Methylnaphthalene predominantly reacts with 5 at the NMR (5 204.10 and 1H-NMR o 9.94, which are consistent

2-position. While 1,3,5-trimethylbenzene is inert to 1, the with vinyl cation. To our knowledge, this is the first spectro- reaction of 5 proceeds smoothly. scopic detection of a vinyl cation species attached to a hydro- The origin of the o-selectivity in the reaction of 5 is not gen atom. Such cation is known to be extremely reactive.16 clear at present. An ene-reaction mechanism, however, can A C-H coupling constant of J=180 Hz is obtained by het- be ruled out (Figure 5): Reaction of 5 with CD3C6H5 gives eronuclear J-spectroscopy of 13 at the cationic center, which the product possessing a CD3 group, and no scrambling of reveals an sp2-structure. Probably, an ion-paired sp2 vinyl deuterium at the olefin moiety is observed. Other possibili- cationic species, and not a free vinyl cation, is formed. ties are i) interaction of the benzylic proton and electrophile Scheme 8 C-C triple bond at the transition state (C-H/ƒÎ interaction), and ii) initial ipso-substitution followed by the migration of the alkenyl group to the adjacent aromatic carbon. The m-selectivity in the reaction of t-butylbenzene might be explained by the latter interpretation. Elucidation of the mechanism is a subject for future study.

The origin of the selective trimerization may also be inter-

esting. When the reaction mixture containing 13 is treated

with excess m-xylene, no electrophilic substitution occurs.

Since a complex of silylethyne and GaC13 reacts with the aro-

matic hydrocarbon, 13 apparently is less reactive. Presum-

ably, the inertness of 13 is one reason for the termination of

the oligomerization. Figure 5 This reaction reveals that the complex formed from GaC13

2.3 Electrophilic Trimerization of Silylethyne and the C-C triple bond is reactive enough to be attacked by

The activated acetylene can be attacked not only by an a relatively non-nucleophilic alkyne ƒÎ-electron. It should aromatic compound but also by silylethyne. When triethylsi- also be noted that, in the presence of GaC13, otherwise unsta-

lylethyne is treated with GaC13 at -78 •Ž for 1.5 h, sequen- ble cationic species can be generated and react with other tial C-C bond formations take place to give a trimeric reagents. The cationic species 13 gains a life-time long

derivative (Scheme 7).6 Addition of an alkylmagnesium or enough to be attacked by an organometal reagent. As

alkyllithium compound followed by aqueous workup gives a described in Scheme 2, arenium cation 2 also appears to be

conjugated triene. A noteworthy aspect of the reaction is considerably stabilized, and addition of a base such as MeLi

that a terminal carbon atom of the hexatriene is alkylated or THE is required for their aromatization. Stable arenium is

with the organometallic reagent. In addition, the other ter- also detected in the reaction of 1,2,3-trimethoxybenzene

minal carbon atom is attached to the gallium metal. The for- (Scheme 3). This feature is another interesting aspect of the

Vol.58 No.11 2000 ( 9 ) 1033

organogallium chemistry using GaC13. in benzene,21 and are reasonably assumed to possess a ƒÎ-

coordinated structure. The strong perturbations on the 3. Carbogallation Reactions electrons exerted by the GaC12 probably destabilize ƒÎ- the

Organogallium dichloride undergoes carbometalation with alkynylgallium, which collapses to enyne via carbogallation.

the C-C triple bond (carbogallation). Probably, the initial Allylgallium generated from allylsilane and GaC13 under-

step of the carbogallation is the interaction of the Lewis goes allylgallation with silylalkyne (Scheme 11).18 Treatment acidic gallium metal with the ƒÎ-bond (Scheme 9). Then it of alkynyltrimethylsilane and allyltrimethylsilane with GaC13

rearranges to the four-membered transition state for the car- at room temperature for 30 min, which is followed by methyl-

bogallation. We first came across this reaction in the dimer- magnesium bromide and water, gives 1-trimethylsily1-2-sub-

ization of alkynylgallium.17 Later, it was extended to the stituted-1,4-diene. Although silylalkyne is capable of under-

reactions of allylgallium,18 gallium enolate,19 and gallium going self-dimerization as described in Scheme 10, this

phenoxide.2° Using derivatives of ethyne, ethenylation cross-coupling reaction is more rapid. The C-C bond for-

(C2-olefination) of these organogallium compounds can also mation occurs regioselectively at the ƒÀ-carbon atom of sily- be successfully conducted. Generally the C-C triple bond lalkynes. It is shown that the silyl group in the product is

needs to be activated either as alkynylgallium or alkynylsilane derived from silylalkyne, and involvement of allylgallation is

towards the carbogallation. We previously described in the demonstrated by deuteration experiment. (E)-Relation

study of alkynylstannane that the SnC13 group attached to between the silyl and allyl group confirms the cis-addition in

the C-C triple bond perturbs the electronic structure of the the carbogallation. π-electron system:9 The SnCl3 group inductively withdraws

electron from the triple bond making its ƒ¿-carbon atom Scheme 11

nucelophilic and the ƒÀ-carbon atom electrophilic. The dis-

cussion explains the reason why the carbostannylation gives

an ƒ¿, ƒ¿-dimetallo species rather than an ƒ¿, ƒÀ-derivative.

Probably, a similar mechanism is involved in the carbogalla-

tion.

Scheme 9

A difference of this allylation from other carbogallation is that the reaction takes place with aryl or alkyl substituted alkynes as well (Scheme 12). It may be due to the higher reactivity of allylgallium compared to that of alkynylgallium, Treatment of alkynyltrimethylsilane with GaC13 in methyl- gallium enolate, or gallium phenoxide (vide supra). The C-C cyclohexane at room temperature for 30 min gives dimeric bond formation occurs at the internal carbon of 1-alkyne. products after aqueous workup (Scheme 10).17 Since treat- While the allylgallation of silylalkynes proceeds via cis-addi- ment of an alkynyllithium and an alkynyltributyltin with tion, deuteration experiments indicate that mixtures of iso- GaC13 also gives the same enyne compound, an alkynylgalli- mers are obtained from 1-alkynes depending on the sub- um intermediate must be involved in these reactions. The stituents. Cis-addition predominates with secondary and ter- first step of this reaction may be ƒÎ-coordination of tiary 1-alkynes, while trans-addition takes place with prima- silylethyne to GaCl3. While the complex is stable at low tem- ry and aryl derivatives. Some parts of the mechanisms differ peratures as shown in Scheme 2, transmetalation from silicon in the allylgallation of silylacetylene and 1-alkyne. to gallium takes place at room temperature liberating Scheme 12 trimethylsilyl chloride. Alkynyldichlorogallium then sponta- neously dimerizes to give a 1, 1-digallio-l-buten-3-yne derivative, which is converted to a conjugated enyne by protodegallation. Formation of the gallated dimer clearly indicates that the carbogallation takes place between two alkynyl- galliums. Alkynyldimethylgalliums are known to be dimeric Carbogallation between gallium enolate and ethynylgallium

provides a method to vinylate carbonyl a-position.19 Alkyla- Scheme 10 tion of enolate is a fundamental C-C bond formation, and is

used to attach an spa-carbon atom to the carbonyl a-carbon

atom. Such enolate reaction at an sp2-carbon atom, especial-

ly ethenylation (C2-olefination), has been undeveloped, and

only stepwise methods were known.13 Trimethylsilylethyne

and silyl enol ether are reacted with GaCl3 at room tempera-

ture, and after treatment with THE and 6 M H2SO4, ƒ¿-

ethenyl ketone is obtained (Scheme 13). The C-C bond for-

mation is very rapid at room temperature, and is completed

within 5 min. The reaction can be applied to the synthesis of

not only unenolizable ƒ¿-ethenylated ketone but also to an

1034 ( 10 ) J. Synth. Org. Chem., Jpn. enolizable product. Conjugated enone is generally not likely that such reaction also proceeds (Cf. Scheme 10 and detected. Employment of GaCl3 is essential, and no reaction 11). takes place with AlCl3 and InCl3, other Lewis acids of the Gallium is the period 4 element in the group 13, and tin group 13 elements. ƒ¿-Ethenylation of an active methylene the period 5 in the group 14 (Figure 6) : These elements sit compound23 and thioester24 can be conducted as well. diagonally in the periodic table. That organogallium compounds and organotin compounds undergo similar carbomet- Scheme 13 alation might be explicable in relation to the relative posi- tions of these elements.2° Compounds containing elements which sit diagonally in the periodic table sometimes behave similarly. The most famous example is that of lithium and magnesium : Reactions of Grignard reagent and organolithi- The mechanism of this reaction involves carbogallation um reagent are treated in the same category in textbooks. As

(Scheme 14). The transmetalation of silyl enol ether with for the gallium and tin, the similarity in the electronegativity GaCl3 gives gallium enolate, and alkynylgallium is formed of the elements or ionic radius of the ions has been noted. from silylethyne. The carbogallation then leads to ƒÁ, ƒÁ-digal- We here provide examples showing similar reactivity of lio-ƒÀ-enone, which precipitates from the solution. Finally, organogallium and organotin compounds. The concept of deuterodegallation of the intermediate with 6 M D2SO4 in the diagonal elements in the organometallic chemistry might D2O gives the corresponding dideuterated product. be much more general than has been considered. It may be interesting, in that sense, to probe the reactivity of organobis- Scheme 14 muth compound, since bismuth is another diagonal element of tin.

β-Silylethenylation reaction of lithium phenoxide with silylethyne takes place in the presence of GaCl3 via carbogallation (Scheme 15).20 Phenol is lithiated with butyllithium, and then treated with trimethylsilylethyne and GaCl3 at 50 •Ž for 12 h to give ƒÀ-silylethenylated phenol. The reaction takes place at the o-position of the phenol hydroxy group. Lithi- um phenoxide prepared with lithium hydroxide can also be used. Deuteration experiment indicates involvement of the carbogallation between gallium phenoxide and silylethyne.

Scheme 15 Figure 6

To summarize, several interesting properties of organo-

gallium reagents in organic synthesis are described. 1) GaCl3 interacts with ƒÎ-compounds generating a highly electrophilic

species. 2) In the presence of GaCl3, certain cationic species

are stabilized thus gaining longer life-time. 3) Organogalli-

um dichlorides undergo carbometalation reaction with a C-C

Noticed during these studies on the carbogallation reaction triple bond. is its similarity to carbostannylation (Scheme 16). Described Acknowledgments We would like to thank the following peo- above are i) carbogallation of gallium enolate with alkynyl- ple who are deeply involved in this project; Mr. T. Tsuk- gallium (Scheme 13), and ii) carbogallation of gallium phe- agoshi, Mr. K. Kobayashi, Ms. F. Yonehara, Mr. K. Akamat- noxide with ethynylsilane (Scheme 15). Tin enolate also su, Ms. C. Miyagawa, Mr. A. Suwa, Mr. S. Yoshimura, Mr. undergoes carbostannylation with alkynyltin,25 and tin phe- S. Morita, and Mr. H. Sugimoto. A fellowship to Y.K. from noxide with ethynylsilane.9 Although we have not examined the Japan Society of Promotion of Science for young alkynylstannylation and allylstannylation in detail, it may be Japanese scientists is also gratefully acknowledged. This

work was supported by grants from the Japan Society of Pro- Scheme 16 motion of Science.

References

1) For recent examples. Kobayashi, S. ; Koide, K.; Ohno, M. Tetrahedron Lett., 1990, 31, 2435. Fukuda, Y. Matsubara, S.; Lambert, C. ; Shiragami, H. ; Nanko, T. ; Utimoto, K. ; Noza- ki, H. Bull. Chem. Soc. Jpn., 1991, 64, 1810. Hashimoto, Y. Hirata, K. ; Kagoshima, H. ; Kihara, N. ; Hasegawa, M.; Saigo, K. Tetrahedron, 1993, 49, 5969. Shibasaki, S. ; Sasai, H. ; Arai, T. Angew. Chem., Int. Ed Engl., 1997, 36, 1236. Han

Vol.58 No.11 2000 ( 11 ) 1035 Y. Huang, Y.-Z. Tetrahedron Lett., 1998, 39, 7751. Chem. Soc., Chem. Commun., 1978, 914. Bruhn, J.; Heimgart- 2) GaCl3 has been used in some Friedel-Crafts reactions. ner, H. ; Schmid, H. Helv. Chim. Acta, 1979, 62, 2630. Chang, Dehaan, F. P. ; Brown, H. C. J Am. Chem. Soc., 1969, 91, T. C. T. ; Rosenblum, M. ; Samuels, S. B. J. Am. Chem. Soc., 4844. Dehaan, F. P. ; Brown, H. C. ; Hill, J. C. J. Am. Chem. 1980, 102, 5930. Kowalski, C. J. ; Dung, J.-S. J Am. Chem. Soc., 1969, 91, 4850. Mukaiyama, T. ; Ohno, T. ; Nishimura, Soc., 1980, 102, 7951. Steglich, W; Wegmann, H. Synthesis, T. ; Suda, S. ; Kobayashi, S. Chem. Lett., 1991, 1059. 1980, 481. Hudrlik, P. F.; Kulkarni, A. K. J Am. Chem. Soc., 3) Eisch, J. J. J Am. Chem. Soc., 1962, 84, 3830. 1981, 103, 6251. Clive, D. L. J.; Russell, C. G. J. Chem. Soc., 4) Yamaguchi, M. ; Kido, Y. ; Hayashi, A. ; Hirama, M. Angew. Chem. Commun., 1981, 434. Ohnuma, T. ; Hata, N. ; Fujiwara, Chem., Int. Ed Engl., 1997, 36, 1313. H.; Ban, Y. J. Org. Chem., 1982, 47, 4713. Kende, A. S.; 5) Kido, Y. Yoshimura, S. ; Yamaguchi, M. ; Uchimaru, T. Bull. Fludzinski, P. ; Hill, J. H. ; Swenson, W. Clardy, J. J Am. Chem. Soc. Jpn., 1999, 72, 1445. Chem. Soc., 1984, 106, 3551. 6) Kido, Y. Yamaguchi, M. J. Org. Chem., 1998, 63, 8086. 23) Arisawa, M. ; Akamatsu, K. ; Yamaguchi, M. in preparation. 7) Yonehara, F.; Kido, Y. Yamaguchi, M. J. Chem. Soc., Chem. 24) Arisawa, M. ; Miyagawa, C. ; Yoshimura, S. ; Kido, Y. Yam- Commun., 2000, 1189. aguchi, M. in preparation. 8) Kido, Y. Yonehara, F.; Yamaguchi, M. Tetrahedron, in press. 25) Yamaguchi, M. ; Hayashi, A. ; Hirama, M. J. Am. Chem. Soc., 9) We reported the ethenylation reaction of phenol: Yamaguchi, 1993, 115, 3362. Hayashi, A. ; Yamaguchi, M. ; Hirama, M. M.; Hayashi, A.; Hirama, M. J. Am. Chem. Soc., 1995, 117, Kabuto, C. ; Ueno M. Chem. Lett., 1993, 1881. 1151. Yamaguchi, M. ; Arisawa, M. ; Omata, K. ; Kabuto, K.; Hirama, M. ; Uchimaru, T. J. Org. Chem., 1998, 63, 7298. 10) For examples : Yuldashev, K. Y. ; Tsukervanik, I. P. J. Gen. PROFILE Chem. USSR, 1964, 34, 2668. Roberts, R. M. ; Abdel-Baset, M. B. J. Org. Chem., 1976, 41, 1698. Schegolev, A. A. ; Smit, Yoshiyuki Kido was born in Osaka in W. A. ; Khurshudyan, S. A. ; Chertkov, V. A. ; Kucherov, V. F 1972. He received his B. Sc. (1995) and Synthesis, 1977, 324. Stang, P. J. ; Anderson, A. G. J. Am. M. Sc. degrees (1997) from Tohoku Uni- Chem. Soc., 1978, 100, 1520. Hrabovsk'y, J. ; Kovac, J. Coll. versity in the Department of Chemistry. Czech, Chem. Commun., 1979, 44, 2096. Ryabov, V. D.; In 1997, he moved to the Graduate Korobkov, V. Y. J. Org. Chem., USSR, 1980, 16, 337. Fan, School of Pharmaceutical Sciences in R.-L. ; Dickstein, J. I. ; Miller, S. I. .1 Org. Chem., 1982, 47, the same university. He received his Ph. 2466. Kitamura, T. ; Kobayashi, S. ; Taniguchi, H. ; Rap- D. degree in 2000, and is now a re- poport, Z. J Org. Chem., 1982, 47, 5003. Ochiai, M. ; Takao- searcher in Fujisawa Pharmaceutical Co. ka, Y. Sumi, K. ; Nagao, Y. J Chem. Soc., Chem. Commun., Ltd. 1986, 1382. Kitamura, T. ; Nakamura, I. ; Kabashima, T.; Kobayashi, S. ; Taniguchi, H. J. Am. Chem. Soc., 1990, 112, 6149. Takeda, T. ; Kanamori, F. ; Matsusita, H. ; Fujiwara, T. Mieko Arisawa is a Research Associate Tetrahedron Lett., 1991, 32, 6563. Sartori, G. ; Bigi,F.; Pasto- at Tohoku University. She was born in rio, A. ; Porta, C. ; Arienti, A. ; Maggi, R. ; Moretti, N.; Yamagata in 1974, and received her B. Gnappi, G. Tetrahedron Lett., 1995, 36, 9177. Sc. (1996) and M. Sc. degree (1998) 11) Lambert, J. B.Tetrahedron, 1990, 46, 2677. from Tohoku University in the Depart- 12) G. A. Olah, "Friedel-Crafts Chemistry", John Wiley & Sons ment of Chemistry. In 1998, she was (1973). R. Taylor, "Electrophilic Aromatic Substitution", John appointed a Research Associate in the Wiley & Sons (1990). Graduate School of Pharmaceutical Sci- 13) See for examples, Krausz, F. ; Martin, R. Bull. Soc. Chim. Fr., ences, Tohoku University. Her research 1965, 2192. Lynch, B. M. ; Chen, C. M. ; Wigfield, Y.-Y. Can. interests are in the areas of organo- J. Chem., 1968, 46, 1141. Hartshorn, S. R. ; Moodie, R. B.; metallic chemistry. Schofield, K. 1 Chem. Soc. (B), 1971, 2454. 14) For some examples showing modest o-selectivity. Olah, G. A.; Kuhn, S. J. ; Flood, S. H. J. Am. Chem. Soc., 1961, 83, 4571. Norman, R. O. C. ; Radda, G. K. J. Chem. Soc., 1961, 3610. Masahiko Yamaguchi is a Professor of Olah, G. A. ; Flood, S. H. ; Kuhn, S. J.; Moffatt, M. E. ; Over- Tohoku University. He was born in chuck, N. A. J. Am. Chem. Soc., 1964, 86, 1046. Olah, G. A.; Fukuoka in 1954, and received his B. Sc. Kuhn, S. J. ; Hardie, B. A. J. Am. Chem. Soc., 1964, 86, 1055. (1977) and Ph. D. degrees (1982) from Davidson, A. J.; Norman, R. O. C. .1 Chem. Soc., 1964, 5404. The University of Tokyo. He joined the An exception using Me3Te+ was reported. Laali, K. ; Chen, H. Department of Industrial Chemistry, Y. Gerzina, R. J. J. Organomet. Chem., 1988, 348, 199. Kyushu Institute of Technology, in 1982 15) Baker, R. ; Eaborn, C. ; Taylor, R. J. Chem. Soc., 1961, 4927. as Assistant Professor, and was promot- Ansell, H. V. Taylor, R. J Chem. Soc. (B), 1968, 526. Vaugh- ed to Associate Professor in 1985. He an, J.; Wright, G. J. J. Org. Chem., 1968, 33, 2580. moved to the Department of Chemistry 16) Okuyama, T. ; Yamataka, H. ; Ochiai, M. Bull. Chem. Soc. at Tohoku University in 1991. During Jpn., 1999, 72, 2761. Also see references cited. 1987 to 1988 he worked as a postdoctor- 17) Yamaguchi, M. ; Hayashi, A. ; Hirama, M. Chem. Lett., 1995, ate fellow at Yale University with Pro- 1093. fessor S. Danishefsky. In 1997, he was 18) Yamaguchi, M. ; Sotokawa, T. ; Hirama, M. J. Chem. Soc., appointed Professor in the Faculty of Chem. Commun., 1997, 743. Pharmaceutical Sciences of Tohoku 19) Yamaguchi, M. ; Tsukagoshi, T. ; Arisawa, M. .1 Am. Chem. University. He received the Chemical Soc., 1999, 121, 4074. Society of Japan Award for Young 20) Kobayashi, K. ; Arisawa, M. ; Yamaguchi, M. Inorg. Chim. Chemists in 1986. His research interests Acta, 1999, 296, 67. are in the area of synthetic methodology 21) Jeffery, E. A. ; Mole, T..I Organomet. Chem., 1968, 11, 393. and functionally interesting compounds. 22) For examples, Koppel, G. A. ; Kinnick, M. D. .1 Chem. Soc., Chem. Commun., 1975, 473. Metcalf, B. W. Bonilavri, E. J.

1036 ( 12 ) J. Synth. Org. Chem., Jpn.