Catalytic asymmetric synthesis of 2,5-dihydrofurans using synergistic bifunctional Ag catalysis
作者:Taoda Shi、Shenghan Teng、Alavala Gopi Krishna Reddy、Xin Guo、Yueteng Zhang、Kohlson T. Moore、Thomas Buckley、Damian J. Mason、Wei Wang、Eli Chapman、Wenhao Hu
DOI:10.1039/c9ob01903k
日期:——
report a bifunctional Ag catalyst promotedintramolecular capture of oxonium ylides with alkynes for the enantioselectivesynthesis of 2,5-dihydrofurans. This represents unprecedented synergistic catalysis of a bifunctional Ag catalyst. Mechanistic studies revealed that [(R)-3,5-DM-BINAP](AgSbF6)2 (9) is likely to be the active catalytic species and that the reaction involves second order kinetics with
A carbene insertion into electron‐deficient C−H bonds of 1,3‐diesters, β‐ketoesters, β‐ketonitriles, and malononitriles was realized by using CuCN/PCy3 as the catalyst. The reaction provides a straightforward approach to the synthetically important multi‐substituted succinic acid derivatives. A plausible reaction mechanism with cyclopropanation/ring opening as key steps was proposed based on control
visible-light-mediated formal carbene insertion reaction of 1,3-diketones with diazoesters for the construction of enantioenriched 1,4-dicarbonyl compounds with a quaternary carbon center. Combining visible light and a Brønsted acid catalyst, chiral 1,4-dicarbonyl compounds were achieved in good yields with high enantioselectivities by a photochemical carbene transfer protocol.
Enantioselective Intramolecular Carbene C–H Insertion Catalyzed by a Chiral Iridium(III) Complex of<i>D</i><sub>4</sub>-Symmetric Porphyrin Ligand
作者:Jing-Cui Wang、Yan Zhang、Zhen-Jiang Xu、Vanessa Kar-Yan Lo、Chi-Ming Che
DOI:10.1021/cs4001656
日期:2013.6.7
The synthesis of iridium(III) complexes containing bulky porphyrin ligands is described. The chiraliridium(III) complex of the D4-symmetric Halterman porphyrin ligand [Ir((+)-D4-Por)Me(L)] (L = solvent) is an effective catalyst for enantioselective intramolecular carbene insertion into saturated C–H bonds of α-diazoesters, giving the corresponding cis-β-lactones in good isolated yields (up to 87%)
描述了含有庞大的卟啉配体的铱(III)配合物的合成。D 4-对称Halterman卟啉配体[Ir((+)- D 4 -Por)Me(L)](L =溶剂)的手性铱(III)络合物是将对映选择性分子内卡宾插入饱和C中的有效催化剂α-二重氮酸酯的-H键,以良好的分离产率(最高87%),优异的立体选择性(仅顺式产物)和良好的对映选择性(最高78%ee)提供相应的顺式-β-内酯。
Forming All-Carbon Quaternary Centers by Geminal Difunctionalization of Diazo Compounds with N,N-Disubstituted Anilines and Allylic Carbonates
作者:Qiang Chen、Tingzhong Huang、Ying Shao、Shengbiao Tang、Jiangtao Sun
DOI:10.1021/acs.joc.2c02730
日期:2023.3.3
A novel three-componentreaction of N,N-disubstituted anilines, diazocompounds, and allylic carbonates has been developed by using a rhodium–palladium dual catalysis, providing an effective protocol for the construction of tetrasubstituted esters bearing an all-carbon quaternary center as well as an allylic moiety in one pot.