524-63-0Relevant articles and documents
Enantioselective 1,6-Conjugate Addition of Dialkyl α-Diazo Methylphosphonate to para-Quinone Methides
Chen, Yuan,Yu, Rui,Wang, Min,Huang, Yanmin,Peng, Yungui
, p. 4856 - 4861 (2021)
An asymmetric 1,6-conjugate addition reaction of dialkyl diazomethylphosphonates to para-quinone methides promoted by phase-transfer catalysis has been developed. A series of chiral diarylmethylated diazomethylphosphonates were accessed with up to 85% yields and 99% ee enantioselectivities. The resulting products were further transformed into bioactive compounds, namely, a chiral dihydrocinnoline phosphonate and a chiral α-aminophosphonate, bearing diarylmethine stereogenic centers. (Figure presented.).
A Cation-Directed Enantioselective Sulfur-Mediated Michael/Mannich Three-Component Domino Reaction involving Chalcones as Michael Acceptors
Ding, Ran,Zheng, Bo,Wang, Yan,Peng, Yungui
, p. 4128 - 4131 (2015)
A new approach has been developed for an asymmetric sulfur-mediated three-component intermolecular Michael/Mannich domino reaction using chalcones as Michael acceptors. This reaction is catalyzed by chiral quaternary ammonium salts derived from modified quinine and provides facile access to complex sulfur-containing compounds with three contiguous stereogenic centers in yields of up to 93%, with 95:5 dr and 95% ee. These compounds were further elaborated to give the equivalent of a chiral aza-Morita-Baylis-Hillman reaction involving chalcones and azetidines bearing four chiral centers.
A Catalyst-Controlled Enantiodivergent Bromolactonization
Chan, Yuk-Cheung,Lam, Ying-Pong,Tse, Ying-Lung Steve,Wang, Xinyan,Wong, Jonathan,Yeung, Ying-Yeung
supporting information, p. 12745 - 12754 (2021/08/30)
A catalyst-controlled enantiodivergent bromolactonization of olefinic acids has been developed. Quinine-derived amino-amides bearing the same chiral core but different achiral aryl substituents were used as the catalysts. Switching the methoxy substituent in the aryl amide system from meta- to ortho-position results in a complete switch in asymmetric induction to afford the desired lactone in good enantioselectivity and yield. Mechanistic studies, including chemical experiments and density functional theory calculations, reveal that the differences in steric and electronic effects of the catalyst substituent alter the reaction mechanism.
Enantioselective γ-Alkylation of α,β-Unsaturated Aldehydes Using New Cinchona-Based Primary Amine Catalyst
Huang, Yong-Shuang,Song, Shuang-Gui,Ren, Lei,Li, You-Gui,Wu, Xiang
supporting information, p. 6838 - 6841 (2019/11/11)
New cinchona-based primary amine catalysts were prepared and screened as organocatalysts for the γ-alkylation of α,β-unsaturated aldehydes with bis(4-dimethylaminophenyl)methanol. Catalyst C3 containing acetic acid group yielded γ-alkylated products in good yields (up to 94 %) with up to 90 % ee. This new primary aminocatalyst provide new opportunities to explore novel asymmetric transformations.
