ABSTRACT In this review, the authors summarize the recent results from our group on some highly selective reductions using 1,4-dihydropyridines (DHPs). Considering the similarities of the chemical reactivity of DHPs to coenzyme NAD(P)H, the key issue is to find the effective catalysts to activate DHPs and their substrates. It was found that silica gel effectively activated a DHP for the selective reduction of activated carbon-carbon and carbon-nitrogen double bond. The reduction showed very high chemoselectivity; and the characteristic features of the reaction opened new synthetic routes and was applied to natural product synthesis. (Section 1 and 2). The authors also found that illumination of a visible light in the presence of a photosensitizer could effectively activate a DHP to convert sulfonyl group of β-keto sulfone into hydrogen. This reaction is also highly selective and applied to the synthesis of ketones and to natural product synthesis. (Section 3).
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