Enantioselective desymmetrization of meso-aziridines with aromatic thiols catalyzed by chiral bifunctional quaternary phosphonium salts derived from α-amino acids
摘要:
Desymmetrization of meso-aziridines with aromatic thiols was realized by using alpha-amino acids-derived chiral quaternary phosphonium salts catalysts to provide chiral beta-amino sulfides with high yields (up to 99%) and in moderate enantioselectivities (up to 70%). (C) 2015 Elsevier Ltd. All rights reserved.
Phosphine Catalyst-Controlled Cycloaddition or Dienylation Reactions of Trifluoromethyl Aryl Ketones with Bis-Substituted Allenoates
摘要:
A chemoselective phosphine-catalyzed cyclo-addition or dienylation reaction between trifluoromethyl-substituted ketones and bis-substituted allenoates was described. Under the catalysis of triarylphosphine, the reaction gave a range of trifluoromethylated tetrahydrofurans with broad substrate tolerance and good to excellent stereo-selectivity, while the use of trialkylphosphine switched the reaction pathway to furnish CF3-substituted dienyl tertiary alcohols, chemoselectivey. Moreover, a preliminary study on the asymmetric version of the reaction was also performed, which represents the first example of a phosphine-catalyzed asymmetric reaction between allenoates and carbonyl compounds.
Enantioselective γ-Addition-Driven Cascade of β,γ-Unsaturated Ketones by Ion-Pair Catalysis: Access to Chiral 1,3-Dioxolochroman Scaffolds
作者:Xuemei Wang、Liang Zhou、Hongkui Zhang、Xiaoyu Ren、Guowei Gao、Tianli Wang
DOI:10.1021/acs.orglett.1c03567
日期:2022.1.14
A highlyenantioselective γ-addition-driven cascade of β,γ-unsaturated carbonyl compounds by bifunctional ion-pair catalysis has been developed. With this protocol, a range of functionalized chiral 1,3-dioxolochroman derivatives were prepared in high yields with superior stereoselectivities (>99% ee and >20:1 dr). The utility of this method was demonstrated by one-pot synthesis, scaled-up preparation
Highly Enantioselective Synthesis of Phosphorus‐Containing ϵ‐Benzosultams by Bifunctional Phosphonium Salt‐Promoted Hydrophosphonylation
作者:Song Zhang、Zhenghuai Feng、Chunhui Jiang、Xiaojun Yu、Jianke Pan、Juan Du、Zhiyu Jiang、Yuan Chen、Tianli Wang
DOI:10.1002/chem.202101038
日期:2021.8.5
with diverse biological activities. A series of chiral ϵ-benzosultams bearing phosphorus functionalities was synthesized by catalytic asymmetric hydrophosphonylation in the presence of a bifunctional phosphonium salt catalyst. The desired hydrophosphonylation products were obtained in good yields with high enantioselectivities, and scale-up reactions and further derivations were successfully accomplished
A highly enantioselective1,3-dipolarcycloaddition of imino esters with methyleneindolinones has been realized by using readily available thiourea–quaternary ammonium salts as phase-transfer catalysts, enabling efficient construction of a range of chiral spiro[pyrrolidin-3,3′-oxindoles] in good yields with excellent enantioselectivities under mild conditions.