Rhodium-Catalyzed Asymmetric Arylation-Induced Glycolate Aldol Additions of Silyl Glyoxylates |
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| Authors: | Nolan C. Turman Kendrick L. Smith Evan T. Crawford Jacob G. Robins Kathryn M. Weber Prof. Dr. Shubin Liu Prof. Dr. Jeffrey S. Johnson |
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| Affiliation: | Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290 USA |
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| Abstract: | (Diene)Rh(I) complexes catalyze the stereoselective three-component coupling of silyl glyoxylates, arylboronic acids, and aldehydes to give glycolate aldol products. The participation of Rh-alkoxides in the requisite Brook rearrangement was established through two component Rh-catalyzed couplings of silyl glyoxylates with ArB(OH)2 to give silyl-protected mandelate derivatives. The intermediacy of a chiral Rh-enolate was inferred through enantioselective protonation using a chiral Rh-catalyst. Diastereoselective three-component couplings with aldehydes as terminating electrophiles to give racemic products were best achieved with a bulky aryl ester on the silyl glyoxylate reagent. Optimal enantioselective couplings were carried out with the tert-butyl ester variant using an anisole-derived enantiopure tricyclo[3.2.2.02,4]nonadiene ligand. |
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| Keywords: | Arylation Asymmetric Catalysis Multi-Component Coupling Rhodium Silyl Glyoxylates |
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