N-Indolyltriethylborate: A Useful Reagent for Synthesis of C3-Quaternary Indolenines
摘要:
N-Indolyltriethylborate was found to be a useful reagent for dearomatizing C3-alkylation of 3-substituted indoles with both activated and nonactivated alkyl halides to give C3-quaternary indolenines, pyrroloindolines, furoindoline, and hexahydropyridoindoline under mild reaction conditions. The utility of these reagents was demonstrated in the syntheses of a pyrroloindoline-4-cholestene hybrid and debromoflustramine B.
A general method for regioselective C3-benzylation of indoles has been developed. Various 3-substituted indoles and benzyl methyl carbonates with different electronic properties react under mild conditions to afford a diverse range of 3-benzylindolenine products in good yields.