Abstract
Selective addition of radicals to isonitriles can be harnessed for initiating reaction cascades designed to overcome the stereoelectronic restrictions on homoallylic ring expansion in alkyne reactions and to develop a new general route for the preparation of N-heteroaromatics. This method utilizes alkenes as synthetic equivalents of alkynes by coupling homoallylic ring expansion to yield the formal "6-endo" products with aromatization via stereoelectronically assisted C-C bond scission. Computational analysis of the homoallyic expansion potential energy surface reveals that the indirect 5-exo/3-exo/retro-3-exo path is faster than the direct 6-endo-trig closure, revealing the general exo-preference for the cyclization processes.
Original language | English |
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Pages (from-to) | 4265-4278 |
Number of pages | 14 |
Journal | Journal of Organic Chemistry |
Volume | 82 |
Issue number | 8 |
DOIs | |
State | Published - Apr 21 2017 |
Externally published | Yes |
Funding
This study was supported by the National Science Foundation (Grant CHE-1465142). We are also grateful to NSF XSEDE (TG-CHE160006) and RCC FSU for computational resources. G.d.P.G. is grateful to IBM for the 2016 IBM Ph.D Scholarship.