Reducing Stoichiometric Excess of Base to Catalytic Amount: Revisiting Staudinger Reaction for β-lactam Synthesis

Background: B-lactams have been primarily utilized as a leading class of effective anti-biotics. They have been found to show activity against various diseases, prompting the scientific community to prioritise innovative protocols for their synthesis. The general and well-known syn-thetic strategy involves the classical Staudinger reaction exhibiting [2+2] cycloaddition reaction. However, the protocol utilizes stoichiometric excess of base for efficient product formation. Objective: A smarter and more acceptable approach for the synthesis of B-lactams would be to reduce the excess base to a catalytic amount, furnishing a catalytic version of the Staudinger reac-tion. The modified version can eliminate the hazards arising out of excess use of the base, ultimately promoting the environmentally benign approach. Methods: With this hypothesis, a base-catalyzed approach in dimethyl formamide (DMF) towards the synthesis of B-lactam via Staudinger reaction has been endorsed under moderate reaction conditions. Results: The scope of the substrates was explored with both electron-withdrawing and electron-releasing substitutions in the formation of B-lactam. The reduction of the base amount from stoichiometric to catalytic amount was justified by the involvement of DMF in generating the basic condition for the reaction. Conclusion: It was hypothesized that the decomposition of DMF under the base-catalysed reaction condition can generate dimethylamine, which produces the required basic environment.