A Chiral 6-Membered <i>N</i>-Heterocyclic Carbene Copper(I) Complex That Induces High Stereoselectivity
作者:Jin Kyoon Park、Hershel H. Lackey、Matthew D. Rexford、Kirill Kovnir、Michael Shatruk、D. Tyler McQuade
DOI:10.1021/ol1021756
日期:2010.11.5
A chiral 6-membered annulated N-heterocyclic (6-NHC) copper complex that catalyzes β-borylations with high yield and enantioselectivity was developed. The chiral 6-NHC copper complex is easy to prepare on the gram scale and is very active, showing 10 000 turnovers at 0.01 mol % of catalyst without significant decrease of enantioselectivity and with useful reaction rates.
作者:Dimitri Hirsch-Weil、Khalil A. Abboud、Sukwon Hong
DOI:10.1039/c0cc02211j
日期:——
C
1-symmetric isoquinoline-based chiral diaminocarbene ligands (MIQ) have been developed to block three quadrants of the metal coordination sphere, complementing C2-symmetric biisoquinoline-based ligands (BIQ). MIQ-Cu complexes catalyzed conjugate borylation of various α,β-unsaturated amides in good yields (82–99%) and enantioselectivities (75–87% ee).
versions as electron-rich neutral stereodirecting ancillary ligands for enantioselective transformations. Herein we demonstrate that cyclic (alkyl)(amino)carbene (CAAC) ligands can also engage in asymmetric transformations, thereby expanding the toolbox of available chiral carbenes.
Planar chiral N-heterocyclic carbenes that incorporate an iron sandwich complex into the NHC framework are disclosed for use in organocatalytic and transition metal-catalyzed reactions.
Ferrocene-Based Planar Chiral Imidazopyridinium Salts for Catalysis
作者:Christopher T. Check、Ki Po Jang、C. Benjamin Schwamb、Alexander S. Wong、Michael H. Wang、Karl A. Scheidt
DOI:10.1002/anie.201410118
日期:2015.3.27
Planarchirality remains an underutilized control element in asymmetric catalysis. Factors that have limited its broader application in catalysis include poor catalyst performance and difficulties associated with the economical production of enantiopure planarchiral compounds. The construction of planarchiral azolium salts that incorporate a sterically demanding iron sandwich complex is now reported