Enantioselective Palladium‐Catalyzed Cross‐Coupling of α‐Bromo Carboxamides and Aryl Boronic Acids
作者:Bowen Li、Tiejun Li、Muinat A. Aliyu、Zhen Hua Li、Wenjun Tang
DOI:10.1002/anie.201905174
日期:2019.8.12
report an enantioselective palladium‐catalyzedcross‐coupling between α‐bromo carboxamides and aryl boronic acids, generating a series of chiral α‐aryl carboxamides in good yields and excellent enantioselectivities. The development of a chiral P,P=O ligand was critical in overcoming the second transmetalation issue and allows the first asymmetric palladium‐catalyzedcoupling of α‐bromo carbonyl compounds
Bidentate Hydroxyalkyl NHC Ligands for the Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Grignard Reagents
作者:Magaly Magrez、Yann Le Guen、Olivier Baslé、Christophe Crévisy、Marc Mauduit
DOI:10.1002/chem.201203969
日期:2013.1.21
Demonstrating their potential: Bidentate alkoxy NHC ligands have been used in the copper‐catalyzed asymmetricallylic alkylation of allylphosphates with Grignard reagents (see scheme). The method provides access to tertiary and quaternary chiral centers with high regio‐ and enantioselectivity. The system is also applied to the synthesis of chiral E,E‐dienes, a key structural motif prevalent in natural
Enantioselective<i>ortho</i>-CH Cross-Coupling of Diarylmethylamines with Organoborons
作者:Brian N. Laforteza、Kelvin S. L. Chan、Jin-Quan Yu
DOI:10.1002/anie.201505204
日期:2015.9.14
The commonly used para‐nitrobenzenesulfonyl (nosyl) protecting group is employed to direct the CH activation of amines for the first time. An enantioselective ortho‐CH cross‐coupling between nosyl‐protected diarylmethylamines and arylboronic acid pinacol esters has been achieved utilizing chiral mono‐N‐protected amino acid (MPAA) ligands as a promoter.
A compound of the formula (I):
or a pharmaceutically acceptable salt thereof is disclosed, as well as processes for and intermediates in the preparation thereof, a method of antagonizing endothelin, methods for the inhibition of bone metastases, methods for the prevention of growth of new metastases, methods for the inhibition of bone turnover, and methods for the prevention of bone loss in patients, including cancer patients, using an endothelin ET-A receptor antagonist.
Provided are methods of preparing polymers, such as polyisoprene, polybutadiene, polypiperylene, polycyclohexadiene, poly-β-farnesene, or poly-β-myrcene, using iron complexes. Also provided are novel iron complexes, pre-catalysts, intermediates, and ligands useful in the inventive polymerization system.