Deepak Patel, Santosh Singh Thakur*, Sandip S. Shinde and Pradeep Kumar Pages 960 - 966 ( 7 )
The catalytic asymmetric synthesis of terminal epoxides and 1,2-diols via a hydrolytic kinetic resolution of racemic terminal epoxides using a new bimetallic chiral salen CoIII complex incorporated with La(OTf)3 as a catalyst is reported. The new bimetallic chiral salen CoIII complex bearing La(OTf)3 was prepared in a one-pot procedure by activation and bimetallic complex formation from the inactive Jacobsen chiral salen CoII complex (salen = N, N′-bis(3,5-di-tert-butylsalicylidene)-1,2- cyclohexane-diamine). We observed that C1-symmetric chiral bimetallic Co-complex coordinated with La(OTf)3 works as a chiral catalyst and remarkably increased the reactivity and enantioselectivity in the hydrolytic kinetic resolution of terminal epoxides compared to its monometallic analogues. La(OTf)3 plays a crucial role as an achiral Lewis acid in this process, which is supported by the experimental observation presented. To explore the absolute configuration of glycidyl butyrate a vibrational circular dichroism (VCD) spectra was calculated using density functional theory.
Chiral epoxides, asymmetric catalysis, bimetallic chiral salen complex, hydrolytic kinetic resolution, lewis acid, VCD.
Department of Chemistry, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh, Department of Chemistry, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh, Organic Chemistry Division, National Chemical Laboratory, Pune, Organic Chemistry Division, National Chemical Laboratory, Pune