Fe(III)-Based Tandem Catalysis for Amidomethylative Multiple Substitution Reactions of α‑Substituted Styrene Derivatives

Developing tandem multiple C–H substitution reactions of simple alkenes provides rapid access to structurally complex unsaturated building blocks. Amidomethylative reactions that reserve CC double bonds have been composed sequentially for tandem catalytic substitutions around the CC bonds of alkenes. As a proof-of-concept demonstration, tandem catalytic amidomethylative processes, which effectively form multiple C–C bonds, have been developed to directly and selectively transform α-substituted styrenes into unsaturated N-heterocycles. Using Fe­(OTf)3 as the sole catalyst, the operationally simple protocols employ bench-stable bisamidomethane as the sole reagent to produce hexahydropyrimidines and 1,2,3,6-tetrahydropyridine derivatives. Moreover, the practical catalytic processes constituted facile two-step pathways, from simple α-substituted styrenes, to access unsaturated 1,3-diamine and bispidine derivatives.