Enantioselective synthesis of γ-tetrasubstituted nitrosulfonyl carboxylates and amides via<scp>l</scp>-tert-leucine-derived-squaramide catalyzed conjugate addition of nitrosulfones to acrylates and acrylamides
作者:Kalisankar Bera、Irishi N. N. Namboothiri
DOI:10.1039/c4ob00344f
日期:——
Michael addition of α-nitrosulfones to aryl- and alkyl acrylates and acrylamides proceeds in the presence of 5–10 mol% of an amino acid derived new organocatalyst to provide γ-tetrasubstituted γ-nitro-γ-sulfonyl carboxylates and amides in excellent yields and enantioselectivities. Scale-up of the reaction to multi-grams, convenient recovery of the catalyst and its recyclability without any drop in
Visible Light‐Induced Hydrosilylation of Electron‐Deficient Alkenes by Iron Catalysis
作者:Ling Ding、Kaikai Niu、Yuxiu Liu、Qingmin Wang
DOI:10.1002/cssc.202200367
日期:2022.5.20
Lights ON: A method for iron-catalyzed, visible light-induced hydrosilylation reactions of electron-deficient alkenes was developed. A chlorine radical acted as a hydrogen atom transfer reagent to generate a silyl radical. Radical reacted with the alkene substrate to form a Si−C bond. Atom economy of the method and controllability of the silicon-containing products could become useful in silicon-containing
A photoinduced TBADT-catalyzed one-pot, three-component strategy for the synthesis of alkyl-alkyl sulfones was reported. The developed methodology could tolerate broad functional groups and allow for the late-stage modification of complex molecules.
The palladium-catalyzed remote meta-C–H olefination of geometrically challenging substitutedcinnamates using a nitrile directing group derived from 2-cyanobenzoic acid has been described. This new protocol is applicable to various olefin coupling partners and provides the corresponding meta-olefinated products in very good yields and with high selectivity. In addition, using this methodology, a variety
Cinchona based squaramide catalysed enantioselective Michael addition of α-nitrophosphonates to aryl acrylates: enantioselective synthesis of quaternary α-aminophosphonates
Several cinchona based squaramide catalysts were applied to the asymmetric Michael addition of alpha-nitroethylphosphonates to acrylic acid aryl esters, resulting in high yields and enantioselectivities. The absolute configuration of one of the quaternary alpha-nitrophosphonate adducts was deduced from its experimental and calculated CD spectra. The adducts were reduced to their cyclic aminophosphonates by catalytic hydrogenation. (C) 2013 Elsevier Ltd. All rights reserved.