ChemInform Abstract: SYNTHESIS AND PROPERTIES OF ACETYLENIC ORGANOCHLOROSILANES

Abstract

Die Dichlorsilane (I) reagieren mit den Butyl‐ oder Phenyl‐acetyliden des Natriums (II) zu den Chlorethinyl‐silanen (IIIa)‐(IIId).

Selective Synthesis of Functional Alkynylmono‐ and ‐trisilanes

“…NMR spectra were measured with a DPX 400 Avance (Bruker) with tetramethylsilane Me 4 Si (TMS) as internal standard for 1 H, 13 C, and 29 Si. The external standards for 14 N, 59 Co, and 95 Mo were nitromethane (CH 3 NO 2 ), 0.1  K 3 [Co(CN) 6 ] solution in D 2 O, and 1  alkaline Na 2 MoO 4 solution in H 2 O, respectively.…”

“…However, broadened 1 H and 13 C NMR signals for the cyclopentadienyl group and small additional peaks indicated that isomerization processes occurred in solution. The 59 Co NMR, IR, and UV/Vis data were typical for alkyne Co 2 (CO) 6 complexes. [40][41][42][43][44] Scheme 5.…”

“…As a result of the experiments on the preparation of 1, synthesis routes starting from dibromo-and diiododimethylsilane were suspended from the beginning. PhCϵCLi/Na 1 44-55 % [6,7] Me 2 SiCl 2 PhCϵCH 1 60-80 % autoclave [8] Me Instead, for 5 we applied the amino-protected and the halogenation route (Scheme 2). Reaction of 2 with methanol and subsequently excess acetyl bromide gave 5 in 71 % yield based on Et 2 NMe 2 SiCl and 58 % based on Me 2 SiCl 2 .…”

“…[3] The preparation of this compound by monofunctionalization of dichlorodimethylsilane (Me 2 SiCl 2 ) with phenylethynylmagnesium or -alkali compounds has a low selectivity: only moderate yields of 30-37 % (Mg) [3][4][5] and 44-55 % (Li, Na) [6,7] are reported. Our own experiments with phenylethynylmagnesium bromide (PhCϵCMgBr) gave 27-38 % of 1 {as judged by 29 Si NMR spectroscopy; other products: dimethylbis(phenylethynyl)silane [Me 2 Si(CϵCPh) 2 ] and dichlorodimethylsilane (Me 2 SiCl 2 )} and thus confirmed the literature results.…”

“…The solid was recrystallized from hexane (135 mL) at -20°C and then once again from benzene (3 mL)/hexane (12 mL) at -20°C to give dark brownish-red crystals, which were separated, washed with hexane, and dried in vacuo. The byproduct Cp 2 Mo 2 (CO) 6 , which was easily recognized by its violet color, was removed mechanically under a microscope. 8 (1.710 g, 5.00 mmol) in hexane (30 mL) was added with stirring at room temperature to a solution of 8 (1.130 g, 5.04 mmol) in hexane (25 mL).…”