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.