High regioselectivity in electrochemical α-methoxylation of N-protected cyclic amines
摘要:
N-Protecting groups of alpha-substituted cyclic amines strongly affected the regioselectivity in electrochemical methoxylation of these compounds. Namely, N-acyl derivatives were transformed into alpha'-methoxylated compounds, while N-cyano derivatives changed into alpha-methoxylated derivatives. Furthermore, Lewis acid catalyzed nucleophilic substitution of the alpha-methoxylated compounds protected with cyano group afforded alpha,alpha-disubstituted cyclic amines. (c) 2008 Elsevier Ltd. All rights reserved.
α-Cyanation of N-protected cyclic amines was achieved using a direct electrochemical method. Unsubstituted N-protected cyclic amines were easily cyanated at the α-position using an undivided cell in high yields; moreover, α-cyanation of αâ²-substituted pyrrolidine and αâ²-,βâ²- or γ-substituted piperidines smoothly proceeded in high yield and with high to excellent diastereoselectivity. α-Substituted N-cyano-pyrrolidines and -piperidines were also cyanated at the more substituted position (the α-position) using a divided cell with high yield and high regioselectivity.
High regioselectivity in electrochemical α-methoxylation of N-protected cyclic amines
作者:Samuel S. Libendi、Yosuke Demizu、Yoshihiro Matsumura、Osamu Onomura
DOI:10.1016/j.tet.2008.02.060
日期:2008.4
N-Protecting groups of alpha-substituted cyclic amines strongly affected the regioselectivity in electrochemical methoxylation of these compounds. Namely, N-acyl derivatives were transformed into alpha'-methoxylated compounds, while N-cyano derivatives changed into alpha-methoxylated derivatives. Furthermore, Lewis acid catalyzed nucleophilic substitution of the alpha-methoxylated compounds protected with cyano group afforded alpha,alpha-disubstituted cyclic amines. (c) 2008 Elsevier Ltd. All rights reserved.