Towards 2‐Silaallenes: Synthesis of Spirocyclic Precursors

Abstract

Abstract:Reactions of dichlorodivinylsilane (2) and LitBu in a molar ratio 131 and 1/'2 lead to highly reactive intermediates, which can be trapped by suitable reagents. In the presence of trimethylmethoxysilane, norbornadiene, anthracene and diphenylacetylene, products are formed that provide evidence for the intermediate

Ring-opening mechanism of disilacyclopropylidenoids and trisilacyclopropylidenoid: A theoretical study

“…al reported that trisilacyclosilylidene (14) is by only 2.7 kcal/mol with ZPE correction higher in energy than to trisilaallene (11), which has quite similar geometry to that of 14 at B3LYP/6-31G(d,p) [19]. Likewise, we have determined that 14 is by 2.7, 2.8, 4.4, 5.8, and 6.4 kcal/mol with ZPE correction, higher in energy than 11 at the B3LYP/6-31G(d), B3LYP/6-31 þ G(d,p), B3LYP/ cc-pVTZ, MP2/6-31G(d), and MP2/6-31 þ G(d,p) levels, respectively.…”

“…Veszpremi et al also indicated that one of four possible structural isomers at the Si 3 H 4 potential surface, 11, is the highly bent silylene [14]. Therefore, we carried out various theoretical calculations for the bent structure (11), which is dramatically different from those of the carbon analogue, H 2 C]C]CH 2 , and from 1-silaallenes [18,19]. The most unusual geometrical feature of trisilaallene is its very extreme SiSiSi bond angle of 69.4 at the B3LYP/6-31G(d) level (Fig.…”

“…The electrocyclic ring-opening of 7 to the complex of trisilaallene (11) with LiBr may proceed via concerted pathway without free trisilacyclopropylidene. To investigate the feasibility of the concerted mechanism, the relevant transition structure TS3(7 / 11) for the isomerization of 7 to the complex of trisilaallene (11) with LiBr was firstly located at B3LYP/6-31G(d) level (Fig. 5).…”

“…For TS3(7 / 11), the Si (2) 1.694, respectively, which depict the formation of p-bonds. The optimized final structure is the LiBr complex of trisilaallene (11), which is highly bent at the central silicon atom, with a SiSiSi bending angle of 127.3 (Fig. 5).…”

Synthetic Chemistry of Quadricyclane

“…Despite the fact that 2-silaallene (CH 3 ) 3 CH 2 CH=Si= CHCH 2 C(CH 3 ) 3 (221) was active in cycloaddition to N, no formation of the corresponding cycloadduct was not observed in the reaction with Q [111].…”