Synthesis of Cyclopropanes via 1,3-Migration of Acyloxy Groups Triggered by Formation of α-Imino Rhodium Carbenes

Abstract

A novel and highly efficient synthetic approach to cyclopropanes was realized via 1,3-migration of acyloxy groups triggered by α-imino rhodium carbenes. Excellent chemoselectivity ensured broad compatibility of common functional groups. Merits such as readily available substrates, mild reaction conditions, and time-saving processes qualified this transformation as an attractive alternative strategy to synthesize multifunctionalized cyclopropanes. Primary investigations and discussion on the mechanism are presented.

1,2,3-Triazole and Its Analogues: New Surrogates for Diazo Compounds

“…Excellent functional group tolerance and chemoselectivity were achieved. The same group also reported 1,3-migration of the acyloxy group of 162.10 , which furnished highly functionalized cyclopropanes 162.11 in excellent yields …”

Access to tetrahydrocarbazoles and pyrrolo[3,4-b]carbazoles through sequential reactions of triazoles and indoles

“…Intramolecular migrations have been widely used in the chemistry of rhodium carbene due to the inherent nucleophilicity. 9,10 Among them, the 1,2-sulfur (or ester) migration of α-sulfur (or ester) triazoles has attracted much attention in recent years. 10 Except for dimerization, 10 a , b the key intermediate α,β-unsaturated imine could participate in the cyclization reaction as an aza-[4C] synthon and [3C] synthon in previous reports (Scheme 1c).…”

Synthesis of α-Amino Cyclobutanones via Formal 1,3-Hydroxy Migration Triggered by Formation of α-Imino Rhodium Carbene

“…The following combination of a carbocation and a carbanion may afford cyclobutanone 9. 7 It is well-known that cyclobutane motifs are common in pharmaceuticals and bioactive molecules (Figure 1). 8 Moreover, α-amino cyclobutanone is a unique mimic of β-lactam in medicinal chemistry; for instance, it could be employed as an imitator of penicillin in binding to isopenicillin N synthase 8d or as an inhibitor of serine hydrolases and proteases and of metalloenzymes.…”