Premium
Solvent‐Free Hydrosilylation of Terminal Alkynes by Reaction with a Nonclassical Ruthenium Hydride Pincer Complex
Author(s) -
Conifer Christopher,
Gunanathan Chidambaram,
Rinesch Torsten,
Hölscher Markus,
Leitner Walter
Publication year - 2015
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201403016
Subject(s) - hydrosilylation , chemistry , alkyne , phenylacetylene , ruthenium , pincer movement , medicinal chemistry , catalysis , hydride , pincer ligand , reductive elimination , photochemistry , reactivity (psychology) , oxidative addition , organic chemistry , metal , medicine , alternative medicine , pathology
Abstract Upon the simple addition of substrates, the ruthenium pincer complex [Ru( t Bu PNP)(H 2 )(H) 2 ] [ 1 ; t Bu PNP = 2,6‐bis(di‐ tert ‐butylphosphinomethyl)pyridine] is an active and selective catalyst system for the hydrosilylation of terminal alkyl alkynes under mild, solvent‐free conditions. The reactivity of this system for other functionalized terminal alkynes was also investigated, and we observed competing catalytic cycles that produce both alkyne dimers and dehydrogenative silylation products. Kinetic measurements for the hydrosilylation of 1‐octyne show that the catalyst has an initial turnover frequency of 121 h –1 at room temperature. The stoichiometric reaction between 1 and H 2 SiPh 2 yields [Ru( t Bu PNP)(H) 2 (H 2 SiPh 2 )], which undergoes Si–H bond activation to yield the catalytically active species [Ru( t Bu PNP)(HSiPh 2 )(H)]. The reaction of 1 with phenylacetylene yielded [Ru( t Bu PNP)(H) 2 (HC≡CPh)] and [Ru( t Bu PNP)(H)(C≡CPh)(HC≡CPh)], and we propose that the latter is the active species in the dimerization reaction.