Access to P-Stereogenic Phosphinates via N-Heterocyclic Carbene-Catalyzed Desymmetrization of Bisphenols
作者:Zhijian Huang、Xuan Huang、Baosheng Li、Chengli Mou、Song Yang、Bao-An Song、Yonggui Robin Chi
DOI:10.1021/jacs.6b04624
日期:2016.6.22
remote P-stereogenic centers is disclosed. The catalytic reactions can be performed on gram scales with 1 mol % N-heterocycliccarbene (NHC) catalyst, providing efficient access to enantiomerically enriched P-stereogenic phosphinates. The chiral phosphinates prepared with our method can find widespread applications as asymmetric organic catalysts and ligands.
Two new chiral diphenylphosphine dioxides bearing an original bis(triazolyl) backbone were prepared through a two‐step sequence. The key reactioninvolves a copper‐catalyzed [3+2] cycloaddition/dimerization reaction leading to the formation of five bonds in one chemical step with 100 % atom efficiency. Interestingly, these ligands exhibited good to excellent catalytic activities as chiral Lewis base
Access to P-chiral phosphine oxides by enantioselective allylic alkylation of bisphenols
作者:Guo-Hui Yang、Yao Li、Xin Li、Jin-Pei Cheng
DOI:10.1039/c8sc05439h
日期:——
enantioselective desymmetrization reaction of bisphenol compounds with achiral Morita–Baylis–Hillman carbonate agents was developed. Through the asymmetric allylic alkylation strategy, a broad range of optically active P-stereogenic phosphine oxides were generated with excellent to good yields (up to 99%) and high enantioselectivities (up to 98.5 : 1.5 e.r.). The reaction was further investigated by the linear
Tandem One-Pot Wittig/Reductive Aldol Reactions in which the Waste from One Process Catalyzes a Subsequent Reaction
作者:Jinni Lu、Patrick H. Toy
DOI:10.1002/asia.201100296
日期:2011.9.5
Putting waste to work: Tandem one‐pot Wittig/reductive aldol reactions have been performed in which the byproduct of the Wittig reaction, Ph3PO, catalyzes the reductive aldol reaction. This methodology is versatile and allows for three different building blocks to be combined in a simple, one‐pot procedure.
Access to <i>P</i>-stereogenic compounds <i>via</i> desymmetrizing enantioselective bromination
作者:Qiu-Hong Huang、Qian-Yi Zhou、Chen Yang、Li Chen、Jin-Pei Cheng、Xin Li
DOI:10.1039/d0sc07008d
日期:——
novel and efficient desymmetrizing asymmetric ortho-selective mono-bromination of bisphenol phosphineoxides under chiral squaramide catalysis was reported. Using this asymmetric ortho-bromination strategy, a wide range of chiral bisphenol phosphineoxides and bisphenol phosphinates were obtained with good to excellent yields (up to 92%) and enantioselectivities (up to 98.5 : 1.5 e.r.). The reaction