The Concise Synthesis of Spiro-Cyclopropane Compounds via the Dearomatization of Indole Derivatives
摘要:
A concise synthesis of spiro-cyclopropane compounds from indole derivatives and sulfur ylides has been developed via a dearomatization strategy. Moreover, the spiro-cyclopropane compounds could be conveniently transformed to rearomatized indole derivatives in the presence of acids.
ABSTRACT A catalyst-freethree-componentreaction of indoles, carbonyls, and arenesulfinic acids performed at room temperature provides direct access to biologically important 3-(1-arylsulfonylalkyl)indoles. This process features mild conditions, low cost, broad substrate scope, and high yields, and mechanistically bis(indolyl)methanes were identified as the key intermediates. GRAPHICAL ABSTRACT
Highly diastereo- and enantioselective synthesis of syn-β-substituted tryptophans via asymmetric Michael addition of a chiral equivalent of nucleophilic glycine and sulfonylindoles
作者:Jiang Wang、Shengbin Zhou、Daizong Lin、Xiao Ding、Hualiang Jiang、Hong Liu
DOI:10.1039/c1cc12619a
日期:——
The asymmetricsynthesis of syn-beta-substituted tryptophan derivatives was carried out by the Michael addition of chiral equivalent of nucleophilic glycine with sulfonylindoles, and high diastereo- and enantioselectivities were achieved. The resulting adducts were readily converted to syn-beta-substituted tryptophans in 96% yield, indicating that the proposed method is a highly efficient route to
Ag-Catalyzed Diastereo- and Enantioselective Synthesis of β-Substituted Tryptophans from Sulfonylindoles
作者:Bao-Hui Zheng、Chang-Hua Ding、Xue-Long Hou、Li-Xin Dai
DOI:10.1021/ol100161n
日期:2010.4.16
The asymmetric catalytic synthesis of beta-substituted tryptophan derivatives was realized in high diastereo- and enantioselectivity by the reaction of glycine derivatives with sulfonylindoles in the presence of catalyst derived from AgCl and a commercially available chiral monodentate phosphoramidite ligand. The resulting adduct was readily converted to beta-substituted tryptophan in 95% overall yield for two steps, which presented a highly efficient route to chiral beta-substituted tryptophan.
InBr<sub>3</sub>: A Versatile Catalyst for the Different Types of Friedel−Crafts Reactions
作者:Ponnaboina Thirupathi、Sung Soo Kim
DOI:10.1021/jo9014613
日期:2009.10.16
Mild and efficient InBr3-catalyzed Friedel−Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with α-amido sulfones at room temperature in CH2Cl2 has been developed. The products undergo further Friedel−Crafts alkylation with heteroaromatic or electron-rich aromatic compounds leading to unsymmetrical or bis-symmetrical triaryl methanes in good yield. α-Amido sulfones are employed
A concise synthesis of spiro-cyclopropane compounds from indole derivatives and sulfur ylides has been developed via a dearomatization strategy. Moreover, the spiro-cyclopropane compounds could be conveniently transformed to rearomatized indole derivatives in the presence of acids.