Photoaccelerated aza-Michael addition of pyrazoles to α, β-unsaturated carbonyl compounds

N-Alkylpyrazoles are an important subclass of pyrazoles due to their good physiological and pharmacological activities. Here, we report photoaccelerated aza-Michael addition of pyrazoles to α, β-unsaturated carbonyl compounds to provide N-alkylpyrazoles. The advantages, including mild conditions, broad scope, ease of scale-up, high atom-economy, avoiding the use of metals, bases, photocatalysts and additives, make the reaction useful and practical.