A Study on the Asymmetric Synthesis of β-Lactams through Double Stereodifferentiating Cycloaddition Reactions
摘要:
The cycloaddition reaction of chiral aminoketenes, generated from their corresponding acid chlorides and triethylamine, with chiral imines is evaluated as the most direct approach for the construction of cis-beta-lactams with the absolute stereochemistry at the C-3 and C-4 positions being controlled by the ketene partner, independently of the absolute stereochemistry of the imine component.
A Study on the Asymmetric Synthesis of β-Lactams through Double Stereodifferentiating Cycloaddition Reactions
摘要:
The cycloaddition reaction of chiral aminoketenes, generated from their corresponding acid chlorides and triethylamine, with chiral imines is evaluated as the most direct approach for the construction of cis-beta-lactams with the absolute stereochemistry at the C-3 and C-4 positions being controlled by the ketene partner, independently of the absolute stereochemistry of the imine component.
well as reaction conditions. Abinitiostudies at MP2/6−31G* and QCISD(T)/6−311G** levels on model compounds provide a rationalization of the experimental results obtained. From the experimental as well as theoretical data it is clear that the presence of the silyl enol group in the intermediate azadiene is crucial in its stabilisation and plays a fundamental role in the conrotatory ringclosure and,