Highly Enantioselective Cobalt-Catalyzed Hydroboration of Diaryl Ketones
作者:Wenbo Liu、Jun Guo、Shipei Xing、Zhan Lu
DOI:10.1021/acs.orglett.0c00293
日期:2020.4.3
A highlyenantioselective cobalt-catalyzed hydroboration of diaryl ketones with pinacolborane was developed using chiral imidazole iminopyridine as a ligand to access chiral benzhydrols in good to excellent yields and ee. This protocol could be carried out in a gram scale under mild reaction conditions with good functional group tolerance. Chiral biologically active 3-substituted phthalide and (S)-neobenodine
is presented. In the presence of Pd(PPh3)4, accessible precursors undergo a Suzuki cross-coupling reaction with 2-(Boc-amino)benzeneboronic acid pinacol ester and then spontaneously undergo deprotection and intramolecular condensation to form the corresponding phenanthridines in one step. This reaction has a wide range of substrates with various functional groups, and the corresponding products have
Palladium(II)‐Catalyzed Intermolecular Cascade Cyclization of Methylenecyclopropanes with Aromatic Alkynes: Construction of Spirocyclic Compounds Containing Indene and 1,2‐Dihydronaphthalene Moieties
作者:Wei Fang、Yin Wei、Min Shi
DOI:10.1002/adsc.201900327
日期:2019.7.11
A palladium(II)‐catalyzed intermolecular cascade cyclization of methylenecyclopropanes with aromatic alkynes is reported in this paper. The reaction involves a migratory insertion of alkyne, an intramolecular Heck‐type reaction, and β‐H elimination, providing a series of spirocyclic compounds containing indene and 1,2‐dihydronaphthalene moieties in moderate to excellent yields upon heating.
An efficient, one-pot synthesis of 4-methylisoquinolines via a cascade Pd-catalyzed Heck reaction, intramolecularcyclization and isomerization has been developed. This reaction has a wide range of substrates with various functional groups, and the corresponding products have been obtained in good yields.
The use of a chiral (NCP)Ir complex as the precatalyst allowed for the discovery of asymmetrictransferhydrogenation of diaryl ketones with ethanol as the hydrogen source and solvent. This reaction was applicable to various ortho-substituted diaryl keontes, affording benzhydrols in good yields and enantioselectivities. This protocol could be carried out in a gram scale under mild reaction conditions
使用手性 (NCP)Ir 配合物作为预催化剂,可以发现以乙醇为氢源和溶剂的二芳基酮的不对称转移氢化。该反应适用于各种邻位取代的二芳基酮,以良好的收率和对映选择性提供苯甲醇。该方案可以在温和的反应条件下以克级进行。通过合成 ( S )-新苯诺定的关键前体突出了催化体系的实用性。