Benzotriazole-Triggered Three-Component Lewis Acid-Catalyzed Ring-Opening 1,3-Aminofunctionalization of Donor–Acceptor Cyclopropanes

Abstract

The use of benzotriazoles as nucleophilic triggers in the three-component Yb(OTf) 3 -catalyzed ring-opening 1,3aminofunctionalization of donor−acceptor (D−A) cyclopropanes is presented. Using N-halo succinimide (NXS) as the third component, the reaction afforded the 1,3-aminohalogenation product in up to an 84% yield. Moreover, using alkyl halides or Michael acceptors as the third components, the 3,1-carboaminated products are formed in up to a 96% yield in a one-pot operation. Employing Selectfluor as the electrophile, the reaction furnished the 1,3-aminofluorinated product in a 61% yield.

Lewis acid-catalyzed one-pot thioalkenylation of donor–acceptor cyclopropanes using in situ generated dithiocarbamates and propiolates

“…6 The second option is a multicomponent coupling, which poses a comparatively greater challenge in execution (Scheme 1, eqn (1)). 7…”

Regioselective C3–H Alkylation of Imidazopyridines with Donor–Acceptor Cyclopropanes

“…The strain energy in cyclopropane is stated to be 115 kJ/mol and this energy drives ring-opening and cycloaddition processes . The push-pull mechanism of DA-cyclopropanes, which are usually referred to as 1,3-dipolar zwitterionic synthons, makes them one of the most sought after building blocks for a number of reactions, including ring-opening events, cycloadditions, and rearrangement procedures. − …”

Ring-Opening 1,3-Sulfonylation-Fluorination of Donor–Acceptor Cyclopropanes: Three-Component Access to γ-Fluorosulfones

“…(3 + 2), (3 + 3), and (3 + 4) cycloadditions have been investigated, and exploited to build a variety of five- to seven-membered ring structures. Ring-opening reactions induced by nucleophiles to monofunctionalize the cyclopropane ring have also been achieved using a variety of heteroatom and carbon nucleophiles; however, 1,3-bisfunctionalization reactions are so far scarcely explored …”