64764-53-0Relevant academic research and scientific papers
Catalyst-Controlled Nitrene Transfer by Tuning Metal:Ligand Ratios: Insight into the Mechanisms of Chemoselectivity
Weatherly, Cale,Alderson, Juliet M.,Berry, John F.,Hein, Jason E.,Schomaker, Jennifer M.
, p. 1649 - 1661 (2017)
Catalyst-controlled, selective nitrene transfer is often challenging when both C-H and C - C bonds are present in a substrate. Interestingly, a simple change in the Ag(I):L ratio (L = bidentate N,N-donor ligand) enables tunable, chemoselective nitrene transfer that favors either C - C bond aziridination using an 1:1 Ag:L ratio (AgLOTf) or insertion into a C-H bond when the Ag:L ratio in the catalyst is 1:2 (AgL2OTf). In this paper, mechanistic studies, coupled with kinetic profiling of the entire reaction course, are employed to examine the reasons for this unusual behavior. Steady-state kinetics were found to be similar for both AgLOTf and AgL2OTf; both complexes yield electronically similar reactive intermediates that engage in nitrene transfer involving formation of a short-lived radical intermediate and barrierless radical recombination. Taken together, experimental and computational studies point to two effects that control tunable chemoselectivity: suppression of aziridination as the steric congestion around the silver center is increased in AgL2OTf and a decrease in the rate of C-H insertion with AgLOTf in comparison to AgL2OTf. The observation that the sterics of Ag catalysts can be varied, with minor effects on the electronic features of the putative nitrene, has important implications for the development of other silver catalysts that enable tunable, site-selective C-H bond aminations.
A one-pot C-H insertion/olefination sequence for the formation of α-alkylidene-γ-butyrolactones
Lloyd, Matthew G.,Taylor, Richard J. K.,Unsworth, William P.
supporting information, p. 2772 - 2775 (2014/06/09)
A one-pot C-H insertion/olefination sequence for the conversion of α-diazo-α-(dialkoxyphosphoryl)acetates into α-alkylidene- γ-butyrolactones is reported. The key C-H insertion process is achieved using a catalytic amount of a dirhodium carboxylate cataly
