An effective and versatile strategy for the synthesis of structurally diverse heteroarylsilanesviaIr(iii)-catalyzed C–H silylation

Abstract

A versatile silylation of heteroaryl C−H bonds is accomplished under the catalysis of a well-defined spirocyclic NHC Ir(III) complex (SNIr), generating a variety of heteroarylsilanes. A significant advantage of this...

Aryl Chloride-Directed Enantioselective C(sp2)-H Borylation Enabled by Iridium Catalysis

“…To further understand the origins of the ligand-controlled regio- and stereoselectivities, next we explored the selectivity-determining transition states with density functional theory (DFT) calculations using ligand CBL4 as a model. Figure shows the optimized structures and relative energies of the competing transition states for selectivity-determining C–H oxidative addition transition states, following previous mechanistic models of related studies. , The most favorable C–H oxidative addition transition state is TS-A , whose free energy is 5.4 kcal/mol more favorable than that of TS-A- rr (the regioisomeric transition state) and 6.7 kcal/mol more favorable than that of TS-A- ee (the enantioisomeric transition state) and in good agreement with the observed selectivities (95:5 rr ; 87% ee). Comparing TS-A and TS-A- rr , the key differentiation is the extra Ir–Cl interaction in TS-A , which is 3.67 Å and confirmed with independent gradient model (IGM) analysis to have favorable noncovalent interaction (Figure ).…”

Facile Benzylic Alkylation of Arenes with Alcohols by Catalysis with a Spirocyclic NHC IrIII Pincer Complex

“…Based on the above experiments and our previous DFT calculations, [8b] a plausible catalytic cycle is proposed in Figure 1. Initially, the hydrogen of the hydroxyl group is transferred to one of the phenyl groups of the catalyst, forming intermediate I that has a cleaved Ph−Ir bond.…”

A direct method to access various functional arylalkoxysilanes by Rh-catalysed intermolecular C–H silylation of alkoxysilanes

“…Since the pioneering work by the Curtis group in 1982, 5 a series of reports on C–H silylations have been published by many research groups (Scheme 1A). 6–11 This seemingly well-established area, however, is still too far from industrial applications because the C–H silylation reactions developed so far are mostly with highly reactive trialkylsilanes to afford trialkylarylsilanes ( i.e. , mostly Et 3 SiAr), which are unable to be utilized as monomers/reagents in silicone material synthesis due to the lack of leaving groups.…”