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Updated: May 5, 2026

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Chelation-controlled additions to α-silyloxy aldehydes: an autocatalytic approach
Ludovic Raffier1, Gretchen R Stanton, Patrick J Walsh
1P. Roy and Diana T. Vagelos Laboratories, University of Pennsylvania , Department of Chemistry, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
Abstract:
The Felkin-Anh model has been widely accepted to describe stereochemical outcomes in nucleophilic additions to α-silyloxy carbonyl compounds. Herein, it is demonstrated that chelation-controlled additions can be performed using dialkylzinc reagents in the presence of chlorotrimethylsilane with good to excellent diastereoselectivities. Ethyl zinc chloride, the Lewis acid responsible for promoting chelation, is generated in situ in an autocatalytic fashion. This approach circumvents its use in stoichiometric amounts.
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