4360-60-5Relevant articles and documents
Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
supporting information, p. 4119 - 4129 (2020/08/10)
A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
Photo-organocatalytic synthesis of acetals from aldehydes
Nikitas, Nikolaos F.,Triandafillidi, Ierasia,Kokotos, Christoforos G.
supporting information, p. 669 - 674 (2019/02/14)
A mild and green photo-organocatalytic protocol for the highly efficient acetalization of aldehydes has been developed. Utilizing thioxanthenone as the photocatalyst and inexpensive household lamps as the light source, a variety of aromatic and aliphatic aldehydes have been converted into acyclic and cyclic acetals in high yields. The reaction mechanism was extensively studied.
Co-catalysis of a bi-functional ligand containing phosphine and Lewis acidic phosphonium for hydroformylation-acetalization of olefins
Li, Yong-Qi,Wang, Peng,Liu, Huan,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
, p. 1798 - 1806 (2016/04/01)
A novel ionic bi-functional ligand of L2 containing a phosphine and a Lewis acidic phosphonium with I- as the counter-anion was prepared and fully characterized. The molecular structure indicated that the bi-functionalities in L2 were well retained without the incompatibility problem for quenching of the acidity of the phosphonium cation by the Lewis basic phosphine fragment or the anionic I- when the incorporated phosphine fragment and the Lewis acidic phosphonium were strictly located in the confined cis-positions. The co-catalysis over L2-Rh(acac)(CO)2 in the ways of synergetic catalysis and sequential catalysis was successfully fulfilled for one-pot hydroformylation-acetalization, which proved not to be the result of the simple mixture of the mono-phosphine (L4) and the phosphonium salt (L4′). In L2, the phosphonium not only acted as a Lewis acid organocatalyst to drive the sequential acetalization of aldehydes, but also contributed to the synergetic catalysis for the preceding hydroformylation through stabilizing the Rh-acyl intermediate with the phosphine cooperatively. The L2-Rh(acac)(CO)2 system is also generally applied to hydroformylation-acetalization of a wide range of olefins in different alcohols. Advantageously, as an ionic phosphonium-based ligand, L2 could be recycled for 7 runs with Rh(acac)(CO)2 together in RTIL of [Bmim]BF4 without obvious activity loss or metal leaching.