PCN Pincer Palladium(II) Complex Catalyzed Enantioselective Hydrophosphination of Enones: Synthesis of Pyridine-Functionalized Chiral Phosphine Oxides as NC<sub>sp<sup>3</sup></sub>O Pincer Preligands
作者:Xin-Qi Hao、Juan-Juan Huang、Tao Wang、Jing Lv、Jun-Fang Gong、Mao-Ping Song
DOI:10.1021/jo5015307
日期:2014.10.17
A series of chiral PCN pincer Pd(II) complexes VI–XIII with aryl-based aminophosphine–imidazoline or phosphinite–imidazoline ligands were synthesized and characterized. They were examined as enantioselective catalysts for the hydrophosphination of enones. Among them, complex IX, which features a Ph2PO donor as well as an imidazoline donor with (4S)-phenyl and N-Tol-p groups, was found to be the optimal
Enantioselective Hydrophosphination of Enones with Diphenylphosphine Catalyzed by Bis(imidazoline) NCN Pincer Palladium(II) Complexes
作者:Xin-Qi Hao、Yong-Wei Zhao、Jing-Jing Yang、Jun-Long Niu、Jun-Fang Gong、Mao-Ping Song
DOI:10.1021/om500144b
日期:2014.4.14
chiral NCN pincer Pd(II) complexes with 1,3-bis(2′-imidazolinyl)phenyl (Phebim) ligands were synthesized via the C–H activation or oxidative addition method. A dinuclear macrocyclic Pd(II) complex was also prepared by reaction of the Phebim-H ligand with PdCl2. All of the new compounds were fully characterized, and X-ray single-crystal structures were obtained for two of the complexes. The Pd(II) complexes
Enantioselective Synthesis of Coumarin Derivatives by PYBOX-DIPH-Zn(II) Complex Catalyzed Michael Reaction
作者:Sumit K. Ray、Pradeep K. Singh、Nagaraju Molleti、Vinod K. Singh
DOI:10.1021/jo301513x
日期:2012.10.5
A potential pharmacologically active chiral 3-substituted 4-hydroxy-2-oxo-2H-chromene skeleton has been synthesized by enantioselectiveMichael addition catalyzed by PYBOX-DIPH-Zn(OTf)2 complex. The methodology has successfully been employed in the synthesis of (R)-Warfarin and another related compounds.
Enantioselective Friedel−Crafts Alkylation of Pyrroles Catalyzed by PYBOX-DIPH-Zn(II) Complexes
作者:Pradeep K. Singh、Vinod K. Singh
DOI:10.1021/ol902360b
日期:2010.1.1
A highly enantioselectiveFriedel−Craftsalkylation of pyrroles with 2-enoylpyridine N-oxides catalyzed by chiral PYBOX-DIPH-Zn(II) complexes has been developed. The catalyst offers substantial substrate scope and furnished alkylated pyrroles in excellent yields (up to 99%) and enantioselectivities (up to >99% ee).
Enantioselective synthesis of 3,4-dihydropyran derivatives via a Michael addition reaction catalysed by chiral pybox–diph–Zn(ii) complex
作者:Sumit K. Ray、Subhrajit Rout、Vinod K. Singh
DOI:10.1039/c3ob40246k
日期:——
An enantioselective Michael addition of cyclic 1,3-dicarbonyls to 2-enoylpyridine N-oxides catalyzed by a chiral pyboxâdiphâZn(II) complex has been developed. The corresponding Michael adducts have been obtained in high yields with up to >99% ee. The Michael adduct has been transformed to biologically active 2,4-disubstituted hexahydroquinoline. A plausible transition-state model has been proposed to explain the stereochemical outcome of the reaction.