Chiral-at-Metal Rh(III) Complex-Catalyzed Decarboxylative Michael Addition of β-Keto Acids with α,β-Unsaturated 2-Acyl Imidazoles or Pyridine
作者:Shi-Wu Li、Jun Gong、Qiang Kang
DOI:10.1021/acs.orglett.7b00220
日期:2017.3.17
chiral-at-metal Rh(III) complex-catalyzed, highly efficient enantioselective decarboxylative Michaeladdition of β-keto acids with α,β-unsaturated 2-acyl imidazoles or pyridine has been developed, affording the corresponding adducts in 94–98% yield with up to 96% enantioselectivity. This protocol exhibits remarkable reactivity, as the complex with a Rh(III) loading as low as 0.05 mol % can catalyze the decarboxylative
Cooperative Lewis Acid Catalysis for the Enantioselective C(sp<sup>3</sup>)–H Bond Functionalizations of 2-Alkyl Azaarenes
作者:Pramod Rai、Satyadeep Waiba、Kakoli Maji、Dibyaranjan Sahoo、Biplab Maji
DOI:10.1021/acs.orglett.1c03387
日期:2021.11.19
Herein, we describe the enantioselective C(sp3)–H bond functionalizations of 2-alkyl azaarenes using a cooperative dual Lewis acid catalysis. An achiral Lewis acidactivates the unactivated azaarene partner without the need for a strong base. Orthogonally, a chiral-at-metal Lewis acidcatalyst enables LUMO lowering and induces chirality. This method tolerates a range of complex molecular scaffolds
Enantioselective Michael addition reactions in water using a DNA-based catalyst
作者:Yinghao Li、Changhao Wang、Guoqing Jia、Shengmei Lu、Can Li
DOI:10.1016/j.tet.2013.05.133
日期:2013.8
EnantioselectiveMichael addition reactions of malononitrile and cyanoesters to α,β-unsaturated 2-acylimidazoles can be achieved in water using a DNA-based catalyst consisting of double-stranded DNA and copper(II) complex. Quantitative conversions and good enantioselectivities (up to 84% ee) are obtained for a wide range of substrates. The UV–vis absorption and circular dichroism (CD) indicate that
An enantioselective sulfa-Michael addition of alkyl thiols to α,β-unsaturated 2-acyl imidazoles catalyzed by a bifunctional squaramide
作者:Rupesh K. Jha、Subhrajit Rout、Harshit Joshi、Arko Das、Vinod K. Singh
DOI:10.1016/j.tet.2019.130800
日期:2020.1
An enantioselective catalytic sulfa-Michael addition of alkyl thiols to α,β-unsaturated 2-acyl imidazoles using bifunctionalorganocatalysts is reported. The methodology works efficiently with low catalyst loading (1 mol%) to furnish sulfa-Michael adducts in excellent yields (up to 98%) and high enantioselectivities (up to 92% ee). A transition state model has been proposed to explain the stereochemical
A number of nitrile-containing chiral molecules were synthesized via asymmetric nucleophilic addition of formaldehyde N,N-dialkylhydrazone as the nitrile equivalent. Chiral N,N′-dioxide/metal salt complexes enabled the asymmetric addition reactions to both isatin-derived imines and α,β-unsaturated ketones, generating amino nitriles and 4-oxobutanenitrile derivatives in good yields with high enantioselectivities