Stereoselective synthesis of dispiroindano pyrrolidines by the [3 + 2] cycloaddition of thiazolo[3,2‐a]indole tethered dipolarophile with azomethine ylides

Abstract

Azomethine ylides generated by the reaction of cyclic ketones, namely ninhydrin, acenaphthene quinone and 11H‐indeno[1,2‐b]‐quinoxalin‐11‐one, with (i) α‐amino acids (ii) primary/secondary amines, have been successfully utilized for one‐pot three‐component [3 + 2] cycloaddition reactions with a thiazolo[3,2‐a]indole containing dipolarophile (in‐turn generated by the reaction of thieno[2,3‐b]indole‐2,3‐dione and dimethyl acetylene dicarboxylate). Dispiro heterocycles were synthesized in excellent yields and with high stereo‐ and regioselectivity.