Synthesis of spirocyclic heterocycles from α,β-unsaturated N-acyliminium ions

Abstract

The reactions of α,β-unsaturated N-acyliminium ions, generated in situ from 4(S)-O-substitutedhydroxy-5-hydroxy-5-vinyl-N-alkylpyrrolidin-2-ones, with allylsilanes and indoles leading to the formation of spirocyclic heterocycles, are reported.

Recent advances in microwave-assisted multicomponent synthesis of spiro heterocycles

“…The structure and electronic properties of these materials make them promising candidates for organic semiconductors, lightemitting diodes, and liquid crystals. [167][168][169][170] They can be tailored optically and electronically due to their molecular properties, which allows their potential application in a wide range of technological elds to expand. The unique properties and diverse applications of spiro heterocycles make them an intriguing class of organic compounds with enormous potential.…”

My 37 years of working with nitrogen heterocycles and alkaloids

“…My research group also pioneered the discovery of cyclization reactions of α,β-unsaturated N-acyliminium ions with tethered bisnucleophiles to provide access to novel spirocyclic and bridged heterocycles and 5,5-disubstituted pyrrolidines (Scheme 35), [84][85][86] including those shown in Scheme 36, that have promising biological activities. The analogous reactions of α-cyclopropyl N-acyliminium ions with tethered bisnucleophiles were also developed leading to novel spirocycles (Scheme 37).…”

Synthesis of 1-Azaspiro[4,5]-7-decen-2-one from L-Asparagine and L-Aspartic Acid

“…13 In 2020 Pyne reported tandem conjugate addition/N-acyliminium spirocyclization of benzyloxy-hydroxylactam 14 to give spirocyclohexene-pyrrolidone 15 or 1-benzylhexahydro-5,8a-methanooxepino [3,2-b]pyrrol-2(1H)-one 16. 14 Herein we report a synthetic procedure for 1-azaspiro[4.5]-7-decen-2-one based on N-acyliminium spirocyclization.…”