Palladium Complexes Bearing Chiral bis(NHC) Chelating Ligands on a Spiro Scaffold: Synthesis, Characterization, and Their Application in the Oxidative Kinetic Resolution of Secondary Alcohols
作者:Dao Zhang、Jueqin Yu
DOI:10.1021/acs.organomet.9b00833
日期:2020.2.24
A series of chiral bis-N-heterocyclic carbene ligands H2[(S)-1a–d]X2 (X = Br, I) on a spiro scaffold and their palladiumcomplexes (S)-2a–d and (S)-3a,b were prepared and applied in the enantioselective oxidative kinetic resolution of secondary alcohols. The corresponding alcohols can be obtained in high yields with moderate to excellent ee values.
一系列手性双- ñ -杂环碳烯配体ħ 2 [(小号) - 1A - d ] X 2(X = Br的,I)上的螺支架和它们的钯络合物(小号) -图2a - d和(小号) -图3a,b中制备和在仲醇的对映选择性氧化动力学拆分施加。可以以中等到极好的ee值高收率获得相应的醇。
Preparation and application of chiral spiro nitrogen-containing ligands for cobalt-catalyzed asymmetric Michael addition
作者:Chao Chen、Shou-Fei Zhu、Xin-Yan Wu、Qi-Lin Zhou
DOI:10.1016/j.tetasy.2006.10.006
日期:2006.10
novel chiral spiro nitrogen-containing ligands, 7,7′-bis(2-pyridinecarboxamido)-1,1′-spirobiindane (abbreviated as SIPAD) and 7,7′-bis(2-quinolinecarboxamido)-1,1′-spirobiindane (abbreviated as SIQAD), were conveniently prepared from 1,1′-spirobiindane-7,7′-dicarboxylic acid in high yields (85% and 84%, respectively) in two steps. The cobalt complexes prepared in situ from Co(OAc)2 and the ligands have
Enantiomerically pure iodoarene (S)-2 and its derivatives (S)-3 to (S)-18 with a spirobiindane scaffold have been synthesized. The evaluation of these new chiral iodoarenes as catalysts in the enantioselective alpha-tosyloxylation of ketones was performed using m-CPBA as a stoichiometric oxidant, and the synthetically useful alpha-tosyloxylated ketones were obtained in up to 58% enantiomeric excess (ee). (C) 2011 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Highly Enantioselective Carbenoid Insertion into SiH Bonds
Two new organocatalysts derived from L-proline and a novel chiral spire, diamine bearing a C, symmetric backbone, were introduced for an asymmetric aldol reaction in moderate to good asymmetric induction in up to 76% ee and high yields. (c) 2006 Elsevier Ltd. All rights reserved.