161403-16-3

Upstream product

• 67-56-1 methanol 
• 398487-05-3 2-tert-butyldimethylsilyl-1-phenyldiazoethane 
• 29681-57-0 tert-butyldimethylsilane 
• 536-74-3 phenylacetylene 
• 85443-40-9 tert‐butyldimethyl(phenylethynyl)silane 

Downstream Products

• 109681-49-4 2-(tert-Butyl-dimethyl-silanyl)-1-phenyl-ethanone 
• 190852-46-1 tert-butyl-dimethyl-((Z)-styryl)-silane 

Relevant academic research and scientific papers

Rhodium complexes of PCNHCP: Oxidative addition of dichloromethane and catalytic hydrosilylation of alkynes affording (E)-alkenylsilanes

New rhodium complexes of PCNHCP have been synthesized by using the silver transfer reagent, [Ag3(PCNHCP) 2Cl]Cl2 (2). In the reaction between 2 and [Rh(COD)Cl]2 in dichloromethane, the pres

Asymmetric Hydrosilylation of β-Silyl Styrenes Catalyzed by a Chiral Palladium Complex

A palladium complex coordinated with a chiral SIPHOS ligand was evaluated as an efficient catalyst for asymmetric hydrosilylation of β-silyl styrenes with trichlorosilane and 23 1,2-bis(silyl) chiral compounds were produced. Good to excellent enantioselec

Geometric E→Z Isomerisation of Alkenyl Silanes by Selective Energy Transfer Catalysis: Stereodivergent Synthesis of Triarylethylenes via a Formal anti-Metallometallation

An efficient geometrical E→Z isomerisation of alkenyl silanes is disclosed via selective energy transfer using an inexpensive organic sensitiser. Characterised by operational simplicity, short reaction times (2 h), and broad substrate tolerance, the reaction displays high selectivity for trisubstituted systems (Z/E up to 95:5). In contrast to thermal activation, directionality results from deconjugation of the π-system in the Z-isomer due to A1,3-strain thereby inhibiting re-activation. The structural importance of the β-substituent logically prompted an investigation of mixed bis-nucleophiles (Si, Sn, B). These versatile linchpins also undergo facile isomerisation, thereby enabling a formal anti-metallometallation. Mechanistic interrogation, supported by a theoretical investigation, is disclosed together with application of the products to the stereospecific synthesis of biologically relevant target structures.

β-silylcarbenes from isolable diazosilanes

Manganese dioxide oxidation of the hydrazone derivative of tert-butyldimethylsilyl acetophenone gave 2-tert-butyldimethylsilyl-1-phenyldiazoethane (17) an isolable diazocompound. Thermal and Rh(II)-catalyzed decomposition of diazosilane 17 in cyclohexane led to 1-tert-butyldimethylsilyl-1-phenylethylene (19) as the major product. The formation of alkene 19 presumably involves (tertbutyldimethylsilyl)methylphenylcarbene (21), which undergoes preferential 1,2-silyl migration as opposed to 1,2-hydrogen migration. Thermal decomposition of 17 in cyclohexane under oxygen gave substantial amounts of tert-butyldimethylsilyl acetophenone, presumably by reaction of the intermediate carbene with oxygen. Thermal decomposition of 17 in methanol led to alkene 19 and 2-tert-butyldimethylsilyl-1-methoxy-1-phenylethane (22) as major products, along with a significant amount of trans-1-tert-butyldimethylsilyl-2-phenylethylene (20). Kinetic studies indicate that these products are not derived from acid-catalyzed decomposition of the diazocompound 17. Formation of the methyl ether product 22 suggests the involvement of a β-silyl carbocation intermediate, and solvent isotope effect studies indicate that this cation is at least partially derived from protonation of diazocompound 17 by neutral methanol. Photochemical decomposition of 17 in methanol produced the alkene 19 (97%) along with a small amount (2.4%) of the methyl ether 22. Capture of a photochemically generated carbene 21 by methanol is the proposed origin of this minor product. Geometry optimization of trimethylsilylmethylphenylcarbene (8) and carbene 21 at the HF/6-31G* computational level led to a conformation consistent with a hyperconjugative interaction between the vacant p-orbital of these carbenes and the adjacent C-Si bond. Carbenes 8 and 21 are not energy minima at the B3LYP/6-31G* level, where they rearrange to alkenes without barrier via silyl migration. These theoretical findings contrast with the proposed trapping of carbene 21 by methanol and oxygen.

Dehydrogenative silylation of terminal alkynes by iridium catalyst

Dehydrogenative silylation of terminal alkynes with hydrosilanes proceeds in the presence of iridium catalyst to afford the corresponding silylacetylenes. When phenylacetylene and triethylsilane were heated in dry DME in the presence of Ir4(CO)12-PPh3, (2-phenylethynyl)triethylsilane was obtained in 96% yield with little of hydrosilylated products. The present method is applicable for a variety of terminal alkynes and hydrosilanes to give the corresponding silylacetylenes in good yields with high selectivities. (C) 2000 Elsevier Science Ltd.

Transition Metal Complexes of Troeger's Base and their Catalytic Activity for the Hydrosilylation of Alkynes

Rhodium(III) and iridium(III) complexes of Troeger's base (TB), of structural type TB*2MCl3 (M=Rh, Ir), were prepared by treatment of TB with MCl3.The rhodium complex readily catalyzed the hydrosilylation of alkynes with high regio- and stereoselectively observed in some cases.