Room-Temperature Synthesis of Trisubstituted Allenylsilanes via Regioselective C–H Functionalization
摘要:
A Rh(III)-catalyzed o-C-H bond functionalization-based allenylation reaction of allenylsilanes 2 with N-methoxybenzamides 1 affords poly-substituted allenylsilanes with a wide range of attractive functional groups in moderate to excellent yields under very mild conditions (20 degrees C, compatible with ambient air and moisture). Those products may be transformed to different products with attractive structural features. Careful mechanistic studies suggest the reaction proceeds via o-rhodation, regioselective insertion, and beta-H elimination.
A highly regio‐ and stereoselective copper‐catalyzed borylcupration of 1,2‐allenylsilanes affords an unexpected regioreversed allylic boronate bearing an extra C−Si bond at the 3‐position, with a thermodynamically disfavored Z geometry. Such stereodefined allylic boronates containing an extra alkenyl silane moiety are very useful organodimetallic reagents for organic synthesis.