Base-Catalyzed Selective Reductions And Tandem Reactions Of Amides By Hydrosilanes

The selective reduction with organosilicon hydrides is an appealing methodology.In contrast to metal hydride reduction reagents,hydrosilanes are mild air-and water-stable sources of hydride,and can be activated under mild conditions.We have designed and developed two novel base-catalyzed selective hydrosilylation of amides.With base catalysis as a point of convergence,a new protocol for synthesizing isoquinolines was obtained by combining the hydrosilylation of imide with rearrangement.This method breaks through the limitation of using phenylacetylene compounds as precursors for the synthesis of isoquinolines,and 3-aryl isoquinolines were generated in good yields by using available N-benzylphthalimides as raw material.This protocol showed excellent compatibility for alkyl,alkoxy,halogen,cyano and aromatic heterocycles functional groups.The research on mechanisim indicated that the reduction process and the rearrangement process are interspersed rather than mechanically stepwise.The base-catalyzed selective hydrosilylation of N,N-dimethyl amides by adjusting the activity of the base catalyst and the reductant,the reaction time and other reaction conditions,and aromatic aldehydes were obtained through hydrolysis finally.Accordingly,we have developed the first base-catalyzed selective hydrosilylation of amides to aldehydes,which has excellent chemical selectivity.In addition,the reduction of different substituted amides is achieved by adjust the solvents and equivalents of hydrosilane.