Reaction optimization using solid-phase catalysis-CD HTS: Nb-imidazoline-Cu(I)-catalyzed asymmetric benzoylation of 1,2-diols.
Catalytic asymmetric benzoylation of 1,2-diols has been developed using a solid-phase asymmetric catalyst. The reaction conditions were optimized by the screening of different metal salts, solvents, bases, and temperatures. High-throughput screening was performed using circular dichroism detection, and the results revealed that Nb-imidazoline-copper(I) in combination with diisopropylethylamine was able to catalyze with high enantioselectivity, giving the monobenzoylated products in high yields and excellent enantiomeric excesses of up to 95% ee. [reaction: see text]
Arai
Takayoshi
T
Department of Chemistry, Faculty of Science, Chiba University, Inage 263-8522, Japan. tarai@faculty.chiba-u.jp
Mizukami
Tomoe
T
Yanagisawa
Akira
A