A Catalytic Enantiotopic-Group-Selective Suzuki Reaction for the Construction of Chiral Organoboronates
摘要:
Catalytic enantiotopic-group-selective cross-couplings of achiral geminal bis(pinacolboronates) provide a route for the construction of nonracemic chiral organoboronates. In the presence of a chiral monodentate taddol-derived phosphoramidite ligand, these reactions occur with high levels of asymmetric induction. Mechanistic experiments with chiral B-10-enriched geminal bis(boronates) suggest that the reaction occurs by a stereochemistry-determining transmetalation that occurs with inversion of configuration at carbon.
A mild and efficient approach for highly regio- and enantioselective copper-catalyzed hydroboration of 1,1-diaryl substituted alkenes with bis(pinacolato)diboron (B2Pin2) was developed for the first time, providing facile access to a series of valuable β,β-diaryl substituted boronic esters with high enantiomeric purity. Moreover, this approach could also be suitable for hydroboration of α-alkyl styrenes
A Catalytic Enantiotopic-Group-Selective Suzuki Reaction for the Construction of Chiral Organoboronates
作者:Chunrui Sun、Bowman Potter、James P. Morken
DOI:10.1021/ja500029w
日期:2014.5.7
Catalytic enantiotopic-group-selective cross-couplings of achiral geminal bis(pinacolboronates) provide a route for the construction of nonracemic chiral organoboronates. In the presence of a chiral monodentate taddol-derived phosphoramidite ligand, these reactions occur with high levels of asymmetric induction. Mechanistic experiments with chiral B-10-enriched geminal bis(boronates) suggest that the reaction occurs by a stereochemistry-determining transmetalation that occurs with inversion of configuration at carbon.
Chiral Diarylmethanes via Copper-Catalyzed Asymmetric Allylic Arylation with Organolithium Compounds
作者:Sureshbabu Guduguntla、Valentín Hornillos、Romain Tessier、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1021/acs.orglett.5b03396
日期:2016.1.15
A highly enantioselective copper/N-heterocyclic carbene catalyzed allylic arylation with organolithium compounds is presented. The use of commercial or readily prepared aryllithium reagents in the reaction with allyl bromides affords a variety of chiral diarylvinylmethanes, comprising a privileged structural motif in pharmaceuticals, in high yields with good to excellent regio- and enantioselectivities