Isothiourea‐Catalyzed Atropselective Acylation of Biaryl Phenols via Sequential Desymmetrization/Kinetic Resolution
作者:Elizabeth S. Munday、Markas A. Grove、Taisiia Feoktistova、Alexander C. Brueckner、Daniel M. Walden、Claire M. Young、Alexandra M. Z. Slawin、Andrew D. Campbell、Paul Ha‐Yeon Cheong、Andrew D. Smith
DOI:10.1002/anie.201916480
日期:2020.5.11
chiral ligands and catalysts. Despite their utility few simple catalytic methods are available for their synthesis in high enantiopurity. Herein the atropselective acylation of a range of symmetric biaryl diols is investigated using isothiourea catalysis. Studies on a model biaryl diol substrate shows that the high product er observed in the process is a result of two successive enantioselective reactions
Stereoelectronic Characterization and Catalytic Potential of a 1,3‐Bis(2,6‐terphenyl)‐Substituted N‐Heterocyclic Carbene
作者:Daniel Twycross、Christopher J. Davey、Marcus L. Cole、Alasdair I. McKay
DOI:10.1002/ejic.202100148
日期:2021.6.14
The preparation of a 1,3-bis(2,6-terphenyl)imidazol-2-ylidene, IDitop (Ditop=2,6-bis(4-tolyl)phenyl-) is reported. Several late transition metal complexes as well as the selenium adduct of IDitop were prepared to study and compare the stereoelectronic properties of IDitop to other well-known N-heterocyclic carbenes (NHCs). A study of the steric character of IDitop taken from crystal structure data
An air-stable aryl substituted indenyl phosphine used in combination with Pd(OAc)2 provides a highly efficient catalyst for the Suzuki–Miyaura cross-coupling reaction of sterically hindered aryl halides with aryl boronic acids.
A Planar-Chiral Phosphino(alkenyl)ferrocene for Suzuki-Miyaura C-C Coupling Reactions
作者:Dieter Schaarschmidt、Martin Grumbt、Alexander Hildebrandt、Heinrich Lang
DOI:10.1002/ejoc.201402861
日期:2014.10
applied in the presence of palladium in Suzuki–Miyauracouplings for the synthesis of sterically congested biaryls. The catalytic activity arises from homogeneous palladium phosphine complexes, of which the potential pre-catalyst [Pd(4)2Cl2] was characterized structurally. The catalytic system is excellently suited for the synthesis of tri-ortho-substituted biaryls under mild conditions (0.1 mol-%, 50–100