Functionalization of carboxylic acids using sulfoxonium ylides in the presence of [VO­(acac)2] as a catalyst is reported. The usual carbene source, diazo compounds, failed to produce α-carbonyloxy esters in good yield when compared to sulfoxonium ylides. Various standard spectroscopic and analytical techniques were used to characterize the products formed.

Sulfoxonium ylides are the viable alternatives for diazo compounds as carbene precursors. Unlike diazo compounds, these are bench‐stable and crystalline solids. However, the existing methods for the synthesis of sulfoxonium ylides have disadvantages related to the yields, substrate scope, and usage of expensive catalysts. Therefore, it is necessary to develop efficient and competitive protocols for the preparation of sulfoxonium ylides. In this study, we developed an economically affordable protocol for the synthesis of sulfoxonium ylides from diazo compounds using copper powder as a catalyst. This protocol leads to the efficient multigram‐scale synthesis of a wide range of sulfoxonium ylides in good yields. Further, we demonstrated scandium triflate–catalyzed carbene insertion into the N−H bond from sulfoxonium ylide. A variety of anilines and sulfoxonium ylides with various functional groups reacted well and produced the corresponding α‐amino esters in good yields. All the synthesized compounds were characterized using various standard spectroscopic and analytical techniques. We also used computational methods to understand the electronic structure of all the sulfoxonium ylides using geometry optimization, frequency calculation, molecular orbital and natural bond orbital analysis, and energy decomposition analysis. Our computational results revealed that the interaction between carbene and dimethyl sulfoxide is covalent in nature and stable enough to handle in the absence of any catalyst.

Reporting an efficient method for the synthesis of βlactams by the carbonylation of diazo compounds, using [Co 2 (CO) 8 ] to corresponding ketenes, followed by [2 + 2] cycloaddition with imines. The newly developed strategy was successfully applied to electronically and structurally diverse substrates to produce the corresponding β-lactams under mild reaction conditions. Fourier transform infrared spectroscopy was employed to monitor ketene formation and the transformation of ketene into β-lactam. All the products were fully characterized by using various analytical and spectroscopic techniques.