16002-93-0Relevant articles and documents
Saturation transfer and chemical exchange measurements of the stereochemical drift occurring during the Wittig reaction
Pascariu, Aurelia,Mracec, Mircea,Berger, Stefan
, p. 451 - 456 (2005)
The Wittig reaction of butylidenetriphenylphosphorane with benzaldehyde using LiHMDS as base in THF was studied. The stereochemical drift (different ratio obtained in alkenes versus oxaphosphetane intermediates) was followed by low-temperature 1D NMR tech
Synthesis of Functionalized Heteroaromatics: Application to Formal Total Synthesis of Camptothecin
Murata, Naoko,Sugihara, Takumichi,Kondo, Yoshinori,Sakamoto, Takao
, p. 298 - 300 (1997)
The formal total synthesis of camptothecin was achieved via two types of lithiation reactions of pyridine derivatives and a Pd-catalyzed carbonylation of pyridylmethyl methanesulfonates.
Solventless Suzuki coupling reactions on palladium-doped KF/Al2O3
Kabalka, George W.,Pagni, Richard M.,Hair, C. Maxwell
, p. 1423 - 1425 (1999)
(equation presented) A solventless Suzuki coupling has been developed. A commercially available potassium fluoride-alumina mixture is utilized along with palladium black.
Enantioselective copper-catalyzed SN2' substitution with Grignard reagents
Alexakis,Malan,Lea,Benhaim,Fournioux
, p. 927 - 930 (2001)
Cinnamyl chlorides undergo selective SN2' allylic substitution by Grignard reagents using catalytic amount (1 mol%) of CuCN and 1-2 mol% trivalent phosphorus ligand, in dichloromethane. With chiral phosphorus ligands derived from TADDOL ee's up
Heterogeneous Isomerization for Stereoselective Alkyne Hydrogenation to trans-Alkene Mediated by Frustrated Hydrogen Atoms
Zhang, Weijie,Qin, Ruixuan,Fu, Gang,Zheng, Nanfeng
supporting information, p. 15882 - 15890 (2021/10/02)
Stereoselective production of alkenes from the alkyne hydrogenation plays a crucial role in the chemical industry. However, for heterogeneous metal catalysts, the olefins in cis-configuration are usually dominant in the products due to the most important and common Horiuti-Polanyi mechanism involved over the metal surface. In this work, through combined theoretical and experimental investigations, we demonstrate a novel isomerization mechanism mediated by the frustrated hydrogen atoms via the H2 dissociation at the defect on solid surface, which can lead to the switch in selectivity from the cis-configuration to trans-configuration without overhydrogenation. The defective Rh2S3 with exposing facet of (110) exhibits outstanding performance as a heterogeneous metal catalyst for stereoselective production of trans-olefins. With the frustrated hydrogen atoms at spatially separated high-valence Rh sites, the isolated hydrogen mediated cis-to-trans isomerization of olefins can be effectively conducted and the overhydrogenation can be completely inhibited. Furthermore, the bifunctional Rh-S/Pd nanosheets have been synthesized through the surface modification of Pd nanosheets with rhodium and sulfide. With the selective semihydrogenation of alkynes into cis-olefins catalyzed by the small surface PdSx ensembles, the bifunctional Rh-S/Pd nanosheets exhibit excellent activity and stereoselectivity in the one-pot alkyne hydrogenation into trans-olefin, which surpasses the most reported homogeneous and heterogeneous catalysts.
Ready approach to poly(vinyldiphenylphosphine): A novel soluble polymer for conveniently conducting Wittig reactions
Ye, Jing-Jing,Han, Li-Biao
supporting information, (2021/01/25)
The novel poly(vinyldiphenylphosphine) could be easily prepared by using the reactions of the cheap poly(vinyl chloride) with sodium phosphides. Poly(vinyldiphenylphosphine) is soluble in common solvents while its corresponding phosphine oxide is hardly soluble in the solvents. Taking advantage of this different solubility, poly(vinyldiphenylphosphine) could be used as a soluble phosphinopolymer for the Wittig reactions. The reactions could take place efficiently to produce the corresponding olefins while the isolation of the products were simple since the resulted poly(vinyldiphenylphosphine oxide) was not soluble in the solvent and could be easily removed by filtration.