Ruthenium-catalyzed cycloisomerization of 1,1,2,2-tetramethyl-1,2-divinyldisilane: Selective formation of a five-membered silacycle
摘要:
The cycloisomerization of 1,1,2,2-tetramethyl-1,2-divinyldisilane (1) in the presence of ruthenium-diphosphine complexes has been examined. A ruthenium-dppe (8) or a ruthenium-dppv (12) complex selectively catalyzed the reaction and 1,1,2,3,3-pentamethyl-1,3-disilycyclopent-4-ene (3) was isolated as the major product. The reaction was also carried out in the presence of a deuterated ruthenium-P(t)Pr3 complex and the incorporation of deuterium to 1,1,4,4-tetramethyl-1,4-disilacyclohex-2-ene (2) was observed. The mechanism of this reaction has been proposed. (c) 2005 Elsevier B.V. All rights reserved.