Cascade Reactions Initiated by Addition of N-Centered Radicals to Alkynes

3 Cascade Reactions Initiated by Addition of N-Centered Radicals to Alkynes 

In intermolecular reactions, neutral aminyl radicals, R2N , react with n systems preferably by HAT. N-protonation increases the electrophUicity of the radical center, and successful addition of aminium radicals, R2NH, to 7t systems, usually alkenes, has been reported in the hterature. Compared to aminium radicals, amidyl and imidyl radicals, for example, RN C(0)R and [RC(0)]2N , are less electrophilic. Although they are delocahzed 7t-allyl radicals, they react exclusively at nitrogen. Only very few examples for radical cascades that are initiated by addition of A-centered radicals to alkynes have been reported. 

Since the computational studies support the general perception of good or poor leaving groups in self-terminating radical reactions, but clearly contradict the experimental findings, radical cyclization cascades initiated by N-centered radical addition to alkynes are not terminated by homolytic p-fragmentation. 

3 CASCADE REACTIONS INITIATED BY ADDITION OF HIGHER MAIN GROUP (VI)-CENTERED RADICALS TO ALKYNES 

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