The Development of the First Catalyzed Reaction of Ketenes and Imines:  Catalytic, Asymmetric Synthesis of β-Lactams

Abstract

We report practical methodology for the catalytic, asymmetric synthesis of beta-lactams resulting from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines. The products of these asymmetric reactions can serve as precursors to a number of enzyme inhibitors and drug candidates as well as valuable synthetic intermediates. We present a detailed study of the mechanism of the beta-lactam forming reaction with proton sponge as the stoichiometric base, including kinetics and isotopic labeling studies. Stereochemical models based on molecular mechanics (MM) calculations are also presented to account for the observed stereoregular sense of induction in our reactions and to provide a guidepost for the design of other catalyst systems.

Synthesis and Spectroscopic Studies of New Schiff Bases

“…Schiff bases have also been employed as ligands for complexation of metal ions [11]. On the industrial scale, they have wide range of applications such as dyes and pigments [12]. Keeping in view the facts mentioned, we decided to synthesize new Schiff bases which were predicted to have useful biological activity.…”

Synthesis of Novel Azo Schiff Bases and Their Antibacterial and Antifungal Activities

“…Schiff bases are important intermediates for the synthesis of some bioactive compounds such as β-lactams [1][2][3]. Furthermore, they are reported to show a variety of interesting biological actions, including antibacterial [4][5][6][7][8][9], antifungal [4][5]10], anti mouse hepatitis virus (MHV) [11], inhibition of herpes simplex virus type 1 (HSV-1) and adenovirus type 5 (Ad 5) [12], anticancer [13][14][15][16], anti mosquito larvae [17] and herbicidal activities [18].…”

Carbamates I: structural and conformational study of eight methoxyphenyl-N-pyridinylcarbamates

“…2-[(2,4-dichlorophenyl imino) In industry, azomethine dyes have a wide range of application such as dyes and pigments with luminescent properties [1]. These dyes are known to be among most important dyes because of their wide applications, including color photographic system, dye diffusion thermal transfer print system and others [2].…”