182140-48-3Relevant articles and documents
Insertion of alkenyl sulfides into a palladium-aryl bond. 2. Stabilization of σ-yl-κS chelates and decomposition reactions through C-S cleavage
Albe?niz, Ana C.,Espinet, Pablo,Lin, Yong-Shou
, p. 5010 - 5017 (2008/10/09)
The reaction of [Pd(C6F5)Br(NCMe)2] with the allylic sulfides R1SCH2CH=CH2 (R1 = -CH2-CH=CH2, Me), n-BuSCHMeCH=CH2, and n-BuSCH2CH=CHMe results in insertion of the double bond into the Pd-C6F5 bond and β-SR elimination (C-S cleavage) to give the corresponding (pentafluorophenyl)alkenes and a palladium thiolate. With alkenyl sulfides of longer carbon chains RS(CH2)nCH=CH2 (R = n-Bu, Ph; n = 2, 3) five-membered (n = 2, 13, 14) or six-membered (n = 3, 16, 17) σ-yl-τS-palladacycles were obtained. The six-membered derivatives isomerize to the corresponding five-membered palladacycles (18, 19) by one-step Pd-migration (Pd-H elimination-readdition). Inversion of the coordinated sulfur is observed in these derivatives, and the dynamic process has been studied for the monomeric complexes [(σ-κS-(Rthio)alkyl)Pd(acac)] (13b, 14b, 18b, 19b). ΔG?Tc values show that the S-inversion is easier for the Ph-substituted than for the n-Bu-substituted complexes. The decomposition of the σ-yl-κS palladacycles occurs through Pd-migration and, when Pd and S are placed three bonds apart in the chain, β-SR elimination; this is the same process observed in the reaction of [Pd(C6F5)Br(NCMe)2] with allylic sulfides. Double bond isomerization of the (pentaflurophenyl)alkene products formed in the decomposition reactions is observed, catalyzed by Pd-H intermediates. Double pentafluorophenyl arylation is also observed in some cases.
