1259061-70-5Relevant articles and documents
Identification of alkenyl- and arylpalladium hydrides with the aid of hydrosilanes
Chen, Tieqiao,Zhou, Yongbo,Yin, Shuang-Feng,Zhao, Yalei,Goto, Midori,Han, Li-Biao
, p. 1227 - 1229 (2013)
For the first time, the long-proposed thermodynamically unstable catalytic intermediates alkenyl and aryl complexes sp2C-Pd-H have been isolated through the reduction of the palladium acetates with hydrosilanes and subsequent stabilization of t
Facile regio- and stereoselective hydrometalation of alkynes with a combination of carboxylic acids and group 10 transition metal complexes: Selective hydrogenation of alkynes with formic acid
Shen, Ruwei,Chen, Tieqiao,Zhao, Yalei,Qiu, Renhua,Zhou, Yongbo,Yin, Shuangfeng,Wang, Xiangbo,Goto, Midori,Han, Li-Biao
, p. 17037 - 17044 (2011/12/04)
A facile, highly stereo- and regioselective hydrometalation of alkynes generating alkenylmetal complex is disclosed for the first time from a reaction of alkyne, carboxylic acid, and a zerovalent group 10 transition metal complex M(PEt3)4 (M = Ni, Pd, Pt). A mechanistic study showed that the hydrometalation does not proceed via the reaction of alkyne with a hydridometal generated by the protonation of a carboxylic acid with Pt(PEt 3)4, but proceeds via a reaction of an alkyne coordinate metal complex with the acid. This finding clarifies the long proposed reaction mechanism that operates via the generation of an alkenylpalladium intermediate and subsequent transformation of this complex in a variety of reactions catalyzed by a combination of Bronsted acid and Pd(0) complex. This finding also leads to the disclosure of an unprecedented reduction of alkynes with formic acid that can selectively produce cis-, trans-alkenes and alkanes by slightly tuning the conditions.
Highly selective markovnikov addition of hypervalent H-spirophosphoranes to alkynes mediated by palladium acetate: Generality and mechanism
Han, Li-Biao,Ono, Yutaka,Xu, Qing,Shimada, Shigeru
, p. 1086 - 1099 (2010/11/05)
Palladium acetate efficiently catalyzes the addition of an H-spirophosphorane (pinacolato)2PH to alkynes to give Markovnikov addition products highlyselectively. The addition products can be easily converted to the corresponding alkenylphosphonates and phosphonicacids viasimple hydrolysis or thermal decomposition. This new reaction isa general method for the introduction of phosphorus functionality to the internal carbons of terminal alkynes, resolving the problem of the regioselectivity associated with hydrophosphorylation reactions so far reported. Mechanistic studies confirmed that (a) palladium acetate was reduced to metallic palladium by H-spirophosphorane, (b) the P-H bond of H-spirophosphorane could be activated by zero-valent platinum complexes to give the corresponding hydridoplatinum complexes, and (c) an alkenylpalladium species was identified from the reaction of palladium acetate with H- spirophosphorane and diphenylacetylene. These results support a reaction mechanism that palladium acetate was first reduced by H-spirophosphorane to give zero-valent palladium. This zero-valent palladium might insert into the P-H bond of the H-spirophosphorane to give a hydridopalladium species which then added to alkyne via the addition of H-Pd bond to form an alkenylpalladium species with the hydrogen atom added to the terminal carbon of alkynes. Reductive elimination of the alkenylpalladium affords the addition product.
