Alpha-Mono- and -dialkyl derivatives of TOSMIC(R)(p-toluenesulfonyl methylisocyanide) (2, 2a-e) are electroreductively detosylated to give the parent primary and secondary alkyl and aralkyl isocyanides 3 and 3a-e.
1-Trifluoromethylisoquinolines from α-Benzylated Tosylmethyl Isocyanide Derivatives in a Modular Approach
摘要:
The preparation of various 1-triftuoromethyli-soquinolines from alpha-benzylated tosylmethyl isotyanide derivatives and the commercial Togni reagent using a radical cascade is reported. The starting isocyanides are readily prepared in a modular sequence from commercial tosylmethyl isocyanide via sequential double a-alkylation, and the radical reaction proceeds under mild conditions, with high efficiency without any transition-metal catalyst via electron catalysis. This valuable protocol has been successfully applied to the total synthesis of CF3-mansouramycin B.