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Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Grinding-Assisted Organocatalytic Asymmetric Synthesis of Eight-Membered Bridged Biaryls
Solaim1, Namrata Kotwal1, Mohd Naweed1
1Department of Chemistry, Indian Institute of Technology, Jammu 181221, India.
Abstract:
Herein, we disclose a grinding-enabled, enantioselective organocatalytic approach to eight-membered carbocyclic biaryl-bridged frameworks under solvent-free mechanochemical conditions. By employing a hydrogen-bonding organocatalyst, a domino Michael-Henry sequence between indole- or benzothiophene-derived biaryl substrates and β-dicarbonyl compounds proceeds efficiently in a mixer mill, without external solvents or additives. This operationally simple protocol rapidly delivers a rare class of eight-membered bridged biaryls featuring multiple stereocenters and a chiral axis in high yields and excellent enantioselectivities.
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