Functionalized 4-Carboxy- and 4-Keto-2,3-dihydropyrroles via Ni(II)-Catalyzed Nucleophilic Amine Ring-Opening Cyclizations of Cyclopropanes

Abstract

A general synthetic approach to vinylogous 4-carboxy- and 4-keto-2,3-dihydropyrroles is reported using Ni(ClO4)2·6H2O as a Lewis acid catalyst for nucleophilic amine ring-opening cyclizations of donor-acceptor (D-A) cyclopropanes. This methodology provided good to excellent yields of functionalized 2,3-dihydropyrroles under milder reaction conditions than previously reported and is amenable to a variety of D-A cyclopropanes and primary amines.

Asymmetric Ring Opening/Cyclization/Retro‐Mannich Reaction of Cyclopropyl Ketones with Aryl 1,2‐Diamines for the Synthesis of Benzimidazole Derivatives

“…Recently, our group has demonstrated that a chiral N , N′ ‐dioxide/Sc III complex was able to catalyze the ring‐opening reaction of cyclopropyl ketones with amines efficiently, thus generating chiral 2,3‐dihydropyrroles in excellent results. The process is thought to proceed through nucleophilic ring opening of the cyclopropyl ketone to generate A , then intramolecular nucleophilic addition to afford the intermediate B , with subsequent dehydration to give the 2,3‐dihydropyrrole product (path a, Scheme ) ,,…”

Multi‐Objective Optimization of Pseudo‐Dynamic Operation of Naphtha Pyrolysis by a Surrogate Model

“…Synthesis of 20 a. Compound 19 a was synthesized according to a literature method 29. Compound 19 a (0.2 mmol, 61.4 mg) was mixed with FeCl 3 .…”

Metal-mediated synthesis of pyrrolines

“…Synthesis of 2-pyrrolines by nickel catalysis. France et al 131 developed a general synthetic approach to 4-carboxyand 4-keto-2,3-dihydropyrroles 242 using Ni(ClO 4 ) 2 $6H 2 O as a Lewis acid catalyst via nucleophilic primary amine ringopening cyclizations of donor-acceptor (D-A) cyclopropanes 241 (Scheme 77). The optimized conditions were 15 mol% of Ni(ClO 4 ) 2 $6H 2 O with 1.2 equiv.…”