A catalytic one-pot synthesis of sydnone heterocycles with mechanistic insights

We report an efficient catalytic, one-pot, synthesis of sydnone heterocycles from readily available alpha-amino acid derivatives using inexpensive N,N '-dimethylformamide as a precatalyst and oxalyl chloride as a stoichiometric oxidant. This operationally simple procedure benefits from mild conditions and short reaction times as showcased by the synthesis of various substituted sydnone heterocycles in good yields and up to gram scales. In offering mechanistic insight into this reactivity, density functional theory studies are reported. In total, this work documents an effective catalytic strategy for preparing sydnone heterocycles of historic and modern-day importance.