ao7b01846_si_001.pdf (6.71 MB)
To “Rollover” or Not? Stereoelectronically Guided C–H Functionalization Pathways from Rhodium–Abnormal NHC Intermediates
journal contribution
posted on 2018-02-07, 19:22 authored by Champak Dutta, Debasish Ghorai, Joyanta ChoudhuryRollover
C–H activation with transition-metal complexes
has been found to be a difficult but viable pathway to functionalize
potentially chelating molecules, which are otherwise reluctant to
react further. However, selective rollover or nonrollover C–H
activation pathway depends on the stereoelectronic demand of the associated
organometallic intermediate(s). The presented work addresses the above
issue on abnormal N-heterocyclic carbene (NHC) platform. Catalytic
reactions of pyridine-imidazolium substrates with internal alkynes
have been selectively guided toward either rollover or nonrollover
C–H functionalization route via fulfilling the steric and electronic
demands of the relevant rhodium(III)–abnormal NHC metallacyclic
intermediates.