Rhodium-Catalyzed Three-Component Cross-Addition Reactions

2 Rhodium-Catalyzed Three-Component Cross-Addition Reactions 

SCHEME 3.67 Rh-catalyzed 1,3-cycloaddition reactions of carbonyl and azomethine ylides. 

This methodology, typically catalyzed by nickel complexes (see Section 3.3.2.1), has recently been modified by Tanaka et al. [177], replacing the organic boronic acids 

165 by silylacetylenes 168. The (alkenyl)rhodium species obtained by reaction of the rhodium acetylide with alkynyl ester 169 can react with activated alkenes 170 or isocyanides 171 to give an alkyl rhodium intermediate. After suffering a protonation, the latter species affords the 1,3-enynes 172-173 in good yields and with high chemo- and regioselective 

10 examples, 41-84% SCHEME 3.68 Rh-eatalyzed three-eomponent cross-addition reactions. 

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