Design and Synthesis of Polymeric Chiral Bicyclo[3.3.0] Diene as Reusable Ligand for Rhodium-Catalyzed Asymmetric 1,4-Addition
作者:Hongyu Yang、Minghua Xu
DOI:10.1002/cjoc.201201079
日期:2013.1
A series of A‐B type sterically regular bicyclio[3.3.0] diene‐based polymers were designed and synthesized as immobilized chiraldieneligands for asymmetric catalysis. With polymericdiene 6b, good to excellent enantioselectivities can be achieved in Rh‐catalyzed asymmetric 1,4‐addition of arylboronic acids to α,β‐unsaturated ketones.
Design of <i>C</i><i><sub>2</sub></i>-Symmetric Tetrahydropentalenes as New Chiral Diene Ligands for Highly Enantioselective Rh-Catalyzed Arylation of <i>N</i>-Tosylarylimines with Arylboronic Acids
作者:Zhi-Qian Wang、Chen-Guo Feng、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1021/ja0710914
日期:2007.5.1
A new type of C-2-symmetric chiral diene ligand bearing a simple bicyclic [3.3.0] backbone was discovered. (3aS,6aS)-3,6-diphenyl-1,3a,4,6a-tetrahydropentalene was applied successfully in the Rh-catalyzed asymmetric arylation of N-tosylarylimines with arylboronic acids. With the new chiral diene ligand, a broad range of highly enantiomerically enriched diarylmethylamines (98-99% ee) as well as 3-aryl substituted phthalimidines (99% ee) could be easily prepared.
Iridium-Catalyzed Enantioselective Fluorination of Racemic, Secondary Allylic Trichloroacetimidates
作者:Qi Zhang、David P. Stockdale、Jason C. Mixdorf、Joseph J. Topczewski、Hien M. Nguyen
DOI:10.1021/jacs.5b07492
日期:2015.9.23
The Ir-catalyzed enantioselective fluorination of racemic, branched allylic trichloroacetiinidates with Et3N center dot 3HF is a mild and efficient route for selective incorporation of fluoride ion into allylic systems. We herein describe the asymmetric fluorination of racemic, secondary allylic electrophiles with Et3N center dot 3HF using a chiral-diene-ligated Ir complex. The methodology enables the formation of acyclic fluorine-containing compounds in good yields with excellent levels of asymmetric induction and overcomes the limitations previously associated with the eiiantioselective construction of secondary allylic fluorides bearing alpha-linear substituents.