Chem. Rev. 2000, 100, 2159−2231 2159 Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis Fabienne Fache, Emmanuelle Schulz, M. Lorraine Tommasino, and Marc Lemaire* Laboratoire de Catalyse et Synthe`se Organique, UMR 5622, UCBL, CPE, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France Received December 2, 1999 Contents VIII.4.1. Diels−Alder Reactions 2198 VIII.4.2. 1,3-Dipolar Cycloadditions 2203 I. Introduction 2159 VIII.5. Addition of Nucleophiles to CdC Bonds 2204 II. C−H Bond Formation 2161 VIII.5.1. Michael Additions 2204 II.1. Hydrogen as Reducing Agent 2161 VIII.5.2. Free Radical Conjugate Additions 2206 II.1.1. Homogeneous Systems 2162 VIII.6. Hydroformylation 2206 II.1.2. Heterogeneous Systems 2164 VIII.6.1. Regioselective Hydroformylation 2207 II.2. Borohydride and Other Inorganic Hydrides as 2165 Reducing Agents VIII.6.2. Enantioselective Hydroformylation 2207 II.2.1. Homogeneous Systems 2166 VIII.7. Carbonylation 2208 II.2.2. Heterogeneous Systems 2168 VIII.8. Grignard Cross-Coupling 2210 − II.3. Hydride Transfer Reduction 2169 VIII.9. Carbene Insertion into C H Bonds 2210 d II.3.1. Homogeneous Systems 2169 VIII.10. Addition to C O Bonds 2212 II.3.2. Heterogeneous Systems 2171 VIII.10.1. Aldol Reactions 2212 II.4. Hydrosilylation 2172 VIII.10.2. Nucleophilic Addition of Dialkylzinc 2215 III. C−O Bond Formation 2173 Reagents III.1. Epoxidation of Unfunctionalized Olefins 2173 VIII.10.3. Trimethylsilylcyanation 2218 III.1.1. Homogeneous Catalysis 2173 VIII.10.4. Ene Reaction 2220 d III.1.2. Heterogeneous System 2176 VIII.11. Addition of Carbon Nucleophiles to C N 2220 III.2. Dihydroxylation of Olefins 2178 Bonds III.2.1. Homogeneous Systems 2178 VIII.11.1. Addition of Organometallic Reagents to 2220 III.2.2. Heterogeneous System 2178 Imines III.3. Ring Opening of Meso Epoxides 2180 VIII.11.2. Strecker Synthesis 2221 III.4. Kinetic Resolution 2180 IX. Conclusions 2222 III.4.1. Terminal Epoxides 2180 X. References 2224 III.4.2. Secondary Alcohols 2181 IV. C−H Bond Oxidation 2181 IV.1. Allylic and Benzylic Oxidation 2181 I. Introduction IV.2. Baeyer−Villiger-type Reaction 2181 Practical asymmetric catalysis using transition IV.3. Wacker-type Cyclization 2182 metal complexes was inspired by the work of Kagan1 V. S−O Bond Formation 2182 and Knowles.2 Their important results, based on the VI. C−N Bond Formation 2183 use of chiral phosphines as ligands for asymmetric VI.1. Hydroboration/Amination 2183 hydrogenation, have induced a tremendous amount VI.2. Enolate Amination 2183 of work dealing with the synthesis and use of new VI.3. Aza-Claisen Rearrangement 2183 chiral phosphine-containing complexes as catalysts. Numerous catalytic reactions allowing the enanti- VI.4. Azide Synthesis 2184 oselective formation of C-H, C-C, C-O, C-N, and VI.5. Aminohydroxylation 2184 other bonds have been discovered over the last 30 VI.6. Aziridine Synthesis 2184 years, often with spectacular results in terms of VI.7. C−N Bond Formation via S−N Bond 2185 efficiency and selectivity. Formation More recently, asymmetric catalysis has been − VII. C S Bond Formation 2185 developed on a practical scale, since some very VIII. C−C Bond Formation 2185 efficient catalytic industrial processes are currently VIII.1. Allylic Substitutions 2185 carried out to produce chiral building blocks. For VIII.2. Heck Reactions 2193 economic, environmental, and social reasons, interest VIII.3. Cyclopropanations 2193 VIII.4. Cycloaddition Reactions 2198 * To whom correspondence should be addressed. Fax: 33 (0) 4 72 43 14 08. E-mail: [email protected]. 10.1021/cr9902897 CCC: $35.00 © 2000 American Chemical Society Published on Web 05/16/2000 2160 Chemical Reviews, 2000, Vol. 100, No. 6 Fache et al. Fabienne Fache graduated from Ecole Supe´rieure de Chimie Industrielle M. Lorraine Tommasino was born in Mexico and received her Chemistry de Lyon in 1987. She went to the University of Strasbourg where she degree and the Gabino Barreda Medal in 1990 at the University of Mexico worked on geochemistry and steroid synthesis during her Ph.D. studies (UNAM). She then came to France and studied ruthenium dihydrogen in the laboratory of Dr. P. Albrecht. In 1991, she joined the Centre National complexes and their applications in homogeneous catalysis with Bruno de la Recherche Scientifique in the group of Professor M. Lemaire. Apart Chaudret and received her Ph.D. degree from the University of Toulouse from asymmetric catalysis, she is particularly interested in finding new in 1994. In her postdoctoral stay in Paris in Eric Rose’s group, she studied methods for organic synthesis using heterogeneous catalysis. asymmetric oxidations catalyzed with metalloporphyrins. Since 1996 she has had a permanent teaching position “Maıˆtre de confe´rences” at the University of Lyon. Her research interests involve asymmetric homoge- neous catalysis mainly in hydrogenation, hydrosilylation, and hydroformy- lation reactions. Emmanuelle Schulz was born in Cayenne. She graduated from Ecole Supe´rieure de Chimie Industrielle de Lyon in 1989 and received her Ph.D. degree from the University of Lyon in 1992 for studies concerning the total synthesis of Strigol, under the direction of Professor P. Welzel at the Ruhr-Universita¨t Bochum, RFA. After an industrial postdoctoral position Professor Marc Lemaire was born in 1949 in Paris (France). He was at the Research Center La Dargoire (Rhoˆne-Poulenc Agrochimie), she employed several years in the pharmaceutical industry as a technician,and joined the group of Marc Lemaire in 1993. In 1997 she obtained a then he obtained the engineer level (CNAM Paris 1979) and his Ph.D. permanent position at the “Centre National de la Recherche Scientifique” degree at the Paris VI University (Professor J. P. Guette´; “New chlorinating (CNRS). Her research topics include the preparation of “organic materials” reagent”). In 1983 he obtained a postdoctoral position in the University of for various applications: chiral ligands for the heterogeneous asymmetric Groningen (The Netherlands; Professor R. M. Kellogg; “Thiamacrocycles catalysis, organic conducting polymers for asymmetric electrocatalysis, as ligand for asymmetric catalysis”). He returned to Paris and obtained and specific resins for depollution (especially useful for the petroleum an assistant position at CNAM, and then he became a professor at the industry). Unversity of Lyon. His group is working in five main areas: (1) heterogeneous catalysis in fine chemistry, (2) asymmetric catalysis, (3) − in the preparation of enantiomerically pure com- separation science, including new ligands for liquid liquid extraction, new ionoselective materials, new complexing agents for nanofiltration-com- pounds is growing. More than 30 years after the plexation systems, (4) organic conductors, including poly(thiophenes) and discovery of the above-mentioned methods, however, poly(pyrroles), and (5) deep desulfurization of gasoil. most chiral synthons are still produced from natural chiral building blocks or by performing racemic research centers. Several factors are responsible for resolution (either diastereomer separation or kinetic this lack of practical application, particularly the resolution). There is, indeed, no simple and versatile price of the catalyst precursor (both precious metal method for the preparation of chiral molecules: and optically pure ligand) and the difficulties en- numerous competitive methodologies have to be countered in the separation and recycling of the tested to offer, in each particular case, an optimal catalyst. A few processes have, however, permitted solution. high turnovers. In these cases, the cost of the catalyst It appears that the contribution of asymmetric was considered to be negligible and so the catalyst catalysis in the overall production of chiral chemicals was sacrificed during the workup procedure. Apart is much lower than originally expected, which is from these economic considerations, it is almost surprising given the huge amount of work devoted impossible to recycle phosphine-containing catalysts to this subject, in both academic and industrial due to their low stability toward oxidation. Moreover, Nitrogen-Containing Ligands for Asymmetric Catalysis Chemical Reviews, 2000, Vol. 100, No. 6 2161 this strategy is obviously in total contradiction with tion of a stable chiral center on a nitrogen atom is, the general tendency toward ecological care in chemi- however, possible by using bicyclic structures. Indeed, cal industry. In summary, we can conclude that the many chiral centers on nitrogen atoms exist in the chemical and economic characteristics of these cata- chiral pool such as quinine, cinchonine, sparteine, lysts were partly responsible for many problems strychnine, and emetine. Some of these easily avail- encountered in the development of catalytic asym- able chemicals have already given rise to very ef- metric processes. ficient and enantioselective catalysts for both homo- Many evaluations of new chiral phosphorus-con- geneous and heterogeneous systems. taining ligands are found in every issue of the major The second advantage of nitrogen-containing ligands organic chemical journals, but they focus more often lies in the chemistry of the nitrogen functional group on interesting and original properties than on easy itself. The chemistry of nitrogen is not always easy and straightforward synthesis, which is usually but has received abundant attention so that there complicated. To facilitate separation of the product exist,