| Abstract
| - C−H functionalization of benzyl silyl ethers by means of rhodium-catalyzed insertions of aryldiazoacetates can be achieved in a highly diastereoselective and enantioselective manner by judiciouschoice of chiral catalyst or auxiliary. The dirhodium tetraprolinates such as Rh2((S)-DOSP)4 havebeen widely successful as chiral catalysts in the C−H functionalization chemistry of aryldiazoacetates, but give poor enantioselectivity in the reactions of aryldiazoacetates with benzyl silyl etherderivatives. The use of (S)-lactate as a chiral auxiliary resulted in C−H functionalization withmoderately high diastereoselectivity (79−88% de) and enantioselectivity (68−85% ee). The bestresults (91−95% de, 95−98% ee), however, were achieved using Hashimoto's Rh2((S)-PTTL)4 catalyst.
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