SOMOphilic Alkynylation of Unreactive Alkenes Enabled by Iron-Catalyzed Hydrogen Atom Transfer

Abstract

We report an efficient and practical iron-catalyzed hydrogen atom transfer protocol for assembling acetylenic motifs into functional alkenes. Diversities of internal alkynes could be obtained from readily available alkenes and acetylenic sulfones with excellent Markovnikov selectivity. An iron hydride hydrogen atom transfer catalytic cycle was described to clarify the mechanism of this reaction.

Isocyanides as Acceptor Groups in MHAT Reactions with Unactivated Alkenes

“…Additionally, the novel disconnection possibilities arising from the use of alkenes as radical precursors has led to MHAT reactions making significant inroads into the field of total synthesis, 3 a trend likely to increase as more acceptor groups become available in this burgeoning research area. Acceptor groups currently used in MHAT C–C coupling reactions include electron-deficient alkenes, 4 sulfonylhydrazones derived from formaldehyde, 5 nitriles, 6 pyridine salts, 7 imines, 8 N -sulfinylimines, 9 acylsilanes, 10 alkynyl bromides, 11 β-nitroalkenes, 12 and difluoroalkenes. 13 Within our own research group, we have developed novel MHAT reactions employing ketones, 14 aldehydes, 15 Cbz hydrazones, 16 and tosyl hydrazones 17 as viable acceptor groups ( Figure 1 ).…”