double‐activation strategy for α′‐alkylidene cyclic enone substrates that uses a chiral primary amine and 2‐mercaptobenzoic acid to promote regio‐ and chemoselective addition to generate the complex interrupted iminium ion species. Significantly enhanced reactivity and enantioselectivity were observed for β‐regioselective Michael addition and Friedel–Crafts alkylation with malononitriles and indoles, respectively
Bi(OTf)<sub>3</sub>-Catalyzed Alkyl-Intercepted Meyer–Schuster Rearrangement of Propargylic Alcohols for the Synthesis of 1,2,3,5-Tetrasubstituted Pentane-1,5-diones
An alkyl intercepted Meyer–Schuster rearrangement reaction with α,β-unsaturated ketones as the electrophiles was first investigated, which provided a facile method to construct 2-methylene-pentane-1,5-diones. Then the in situgenerated 2-methylene-pentane-1,5-diones underwent a Michael addition to give diverse 2-malononitrile methyl substituted pentane-1,5-diones in a one-pot fashion. This transformation
<b>Iodotrimethylsilane-Mediated Cross-Aldol Condensation: A Facile Synthesis of α,α′-Bis(substituted benzylidene)cycloalkanones</b>
作者:Gowravaram Sabitha、G. S. Kumar Reddy、K. Bhaska Reddy、J. S. Yadav
DOI:10.1055/s-2004-815920
日期:——
A facile and efficient method for the preparation of α,α'-bis(substitutedbenzylidene)cycloalkanones is described for the first time using iodotrimethylsilane generated in situ from chlorotrimethylsilane and sodium iodidein acetonitrile. The reaction proceeds rapidly at room temperature, giving high yields of products.
Condensation of cycloalkanone with aromatic aldehyde and furfural using supported reagents to prepare bis(substituted benzylidene or furfurylidene)cycloalkanone in excellent yields under microwave irradiation.