Synthesis of an [(NHC)2 Pd(SiMe3 )2 ] Complex and Catalytic cis-Bis(silyl)ations of Alkynes with Unactivated Disilanes

Insights into disilylation and distannation: sequence influence and ligand/steric effects on Pd-catalyzed difunctionalization of carbenes

Density functional theory (DFT) calculation has been used to reveal the mechanism of Pd-catalyzed disilylation of carbene, which is a pathway to construct disilylmethane derivatives.

Pd-Catalyzed disilylation: an efficient route to 2,2′-bis(trimethylsilyl)biphenyls via trapping transient dibenzopalladacyclopentadienes with hexamethyldisilane

A palladium-catalyzed disilylation reaction of 2-iodobiphenyls with hexamethyldisilane via trapping transient dibenzopalladacyclopentadienes has been achieved.

Mechanisms for C(sp2)-Si activation of aryltrimethylsilyl groups in palladium-catalysed couplings

Silyl-substituted aromatic compounds can participate as the electrophilic component in palladium-catalysed cross-couplings, and reactivity is enhanced by a neighbouring silyl-group. Products analogous to those obtained from C-H activation chemistry are accessible by this means with the additional benefit of regiochemistry defined by the site of silyl substitution. DFT studies described here show that the mechanism of C-Si cleavage is distinct from previously recognised mechanisms for C-H cleavage, with a cascade of silyl intermediates en route to a stable product. The amide directing-groups are involved only in the stabilisation of palladacyclic intermediates, and are never disposed to activate silicon directly. 5-Membered and 6-membered palladacycles are known to behave differently in coupling reactions and the calculations reveal underlying reasons in the cationic pathways studied here.

Synthesis of Functionalized Hydrazines: Facile Homogeneous (N-Heterocyclic Carbene)-Palladium(0)-Catalyzed Diboration and Silaboration of Azobenzenes

The bis(N-heterocyclic carbene)(diphenylacetylene)palladium complex [Pd(ITMe)2(PhC≡CPh)] (ITMe=1,3,4,5-tetramethylimidazol-2-ylidene) acts as a highly active pre-catalyst in the diboration and silaboration of azobenzenes to synthesize a series of novel functionalized hydrazines. The reactions proceed using commercially available diboranes and silaboranes under mild reaction conditions.

One-Step Synthesis of Siloxanes from the Direct Process Disilane Residue

The well-established Müller-Rochow Direct Process for the chloromethylsilane synthesis produces a disilane residue (DPR) consisting of compounds Me_n Si₂ Cl_6-n (n=1-6) in thousands of tons annually. Technologically, much effort is made to retransfer the disilanes into monosilanes suitable for introduction into the siloxane production chain for increase in economic value. Here, we report on a single step reaction to directly form cyclic, linear, and cage-like siloxanes upon treatment of the DPR with a 5 m HCl in Et₂ O solution at about 120 °C for 60 h. For simplification of the Si-Si bond cleavage and aiming on product selectivity the grade of methylation at the silicon backbone is increased to n≥4. Moreover, the HCl/Et₂ O reagent is also suitable to produce siloxanes from the corresponding monosilanes under comparable conditions.

An experimental and theoretical study into the facile, homogenous (N-heterocyclic carbene)2-Pd(0) catalyzed diboration of internal and terminal alkynes

Pd(ITMe)₂(PhCCPh) is a pre-catalyst in the unprecedented homogenous catalyzed diboration of terminal and internal alkynes.