Are disilacyclopropylidenes and their carbenoids good precursors for the unknown 1,3-disilaallenes?

Citation
N. Sigal et Y. Apeloig, Are disilacyclopropylidenes and their carbenoids good precursors for the unknown 1,3-disilaallenes?, J ORGMET CH, 636(1-2), 2001, pp. 148-156
Citations number
44
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF ORGANOMETALLIC CHEMISTRY
ISSN journal
0022328X → ACNP
Volume
636
Issue
1-2
Year of publication
2001
Pages
148 - 156
Database
ISI
SICI code
0022-328X(20011125)636:1-2<148:ADATCG>2.0.ZU;2-6
Abstract
Ring opening of disilacyclopropylidenes provides a possible route to the ye t unknown 1,3-disilaallenes. To examine the feasibility of this reaction we studied computationally the potential energy surfaces for the elimination of LiCl from cyclo-CSi2H4ClLi (and for comparison also for cyclo-C3H4ClLi), which serve as models for the corresponding substituted systems. On the ba sis of ab initio molecular orbital calculations at the MP2/6-31G(d)//MP2/6- 31G(d) + ZPE level we predict that the activation energy for the conversion of cyclo-CSi2H4ClLi to 1,3-disilaallene ( + LiCl) is only 6.5 kcal mol(-1) , making this reaction a promising strategy for the synthesis of 1,3-disila allenes. This barrier is much smaller than the barrier (42.5 kcal mol(-1)) for the all carbon analogue, cyclo-C3H4ClLi. The differences between the si licon and carbon systems are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.