A metal‐free and direct alkene C−H cyanation is described. Directing groups are not required and the mechanism involves electrophilic activation of the alkene by a cyano iodine(III) species generated in situ from a [bis(trifluoroacetoxy)iodo]arene and trimethylsilyl cyanide as the cyanide source. This C−H functionalization can be conducted on gram scale, and for noncyclic 1,1‐ and 1,2‐disubstuted alkenes
Photocatalytic <i>E</i> → <i>Z</i> Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity
作者:Jan B. Metternich、Denis G. Artiukhin、Mareike C. Holland、Maximilian von Bremen-Kühne、Johannes Neugebauer、Ryan Gilmour
DOI:10.1021/acs.joc.7b01281
日期:2017.10.6
(−)-riboflavin in the eyes of vertebrates to invert the intrinsic directionality of retinal isomerization. Herein, we extend this methodology to include a bioinspired, catalytic E → Z isomerization of α,β-unsaturated nitriles, thereby mimicking the intermediate Opsin-derived, protonated Schiff base in the visual cycle with simple polarized alkenes. Replacement of the iminium motif by a cyano group is well