Formation of a Stable, Lattice-Framework Disilene: A Strategy for the Construction of Bulky Substituents

✍ Scribed by Shigeki Matsumoto; Shinobu Tsutsui; Eunsang Kwon; Kenkichi Sakamoto

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 166 KB
• Volume: 116
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/ange.200460067

✦ Synopsis

Recently, the reversible tetramerization of a diaminosilylene was reported; [12] 1 is a formal tetramer of tri(tertbutyl)cyclopropenylsilylyne. Although the formation pathway of 1 remains uncertain, multistep reactions include the reduction of the silicon-bromine bonds, isomerization, [6, 7, 13] and condensation to build silylene 4, which undergoes dimerization to give 1 (Scheme 1).

Compound 1 is the first disilene that has C 2 -symmetric chirality through the silicon-silicon double bond, although it was obtained as a racemic mixture of (S,S,S,S)-1 and (R,R,R,R)-1 (Scheme 1). The component silylene 4 is also Figure 1. a) Side and b) top ORTEP views of 1. Thermal ellipsoids are drawn at the 50 % probability level. Hydrogen atoms (a and b) and tert-butyl groups (b) were omitted for clarity. Selected bond lengths [] and angles [8]: Si1-Si1* 2.2621(15), C1-Si2 1.894(3), C1-Si1 1.958(3), C6-Si2 1.894(3), C6-Si1 1.976(3), C1-C2 1.573(4), C5-C6 1.581(4), C2-C1-Si1 113.07(18), Si2-C1-Si1 88.22(13), C5-C6-Si1 114.9(2), Si2-C6-Si1 87.71(14), C1-Si1-C6 89.77(12), C1-Si1-Si1* 133.97(10), C6-Si1-Si1* 136.26(11), C4-Si2-C3 147.40(12), C1-Si2-C6 94.22(13), C1-Si1-Si1*-C6* 12.08(15).