Intramolecular donor–acceptor cyclopropane ring-opening cyclizations

Abstract

Cyclization reactions of donor-acceptor (D-A) cyclopropanes are recognized as versatile methods for construction of carbocyclic and heterocyclic scaffolds. In the literature, many examples of these polarized cyclopropanes' reactivity with nucleophiles, electrophiles, and radicals are prevalent. Although intermolecular reactivity of donor-acceptor cyclopropanes is widely reported, reviews that center on their intramolecular chemistry are rare. Thereupon, this tutorial review focalizes on new intramolecular transformations of donor-acceptor cyclopropanes for cycloisomerizations, formal cycloadditions, umpolung reactions, rearrangements and ring-opening lactonizations/lactamizations from 2009 to 2013. Furthermore, the role of D-A acceptor cyclopropanes as reactive subunits in natural product synthesis is underscored.

An Efficient Method for the Synthesis of 2′,3′-Nonsubstituted Cycloalkane-1,3-dione-2-spirocyclopropanes Using (2-Bromoethyl)diphenylsulfonium Trifluoromethanesulfonate

“…1,2) Ring-opening cyclization of doubly activated cyclopropanes has emerged as a powerful method for the synthesis of a variety of carbo-and heterocyclic compounds. [3][4][5][6] Recently, we demonstrated the formation of indole skeletons by employing the ring-opening cyclization of the doubly activated spirocyclopropanes, 2′-arylcyclohexane-1,3-dione-2-spirocyclopropanes 1, with primary amines 7) (Chart 1). The reaction proceeded regioselectively at room temperature (r.t.) to give 2-aryltetrahydroindol-4-ones 2, one of which was easily converted to the 4-hydroxyindole derivative 3.…”

Synthesis and Reactivity of Donor-Acceptor Substituted Aminocyclopropanes and Aminocyclobutanes

“…However, as our work is focusing on intermolecular annulations, we did not enter in the details of these methods. 5 For a review on intramolecular annulations, see [172]. Introducing new functionalities to modulate the reactivity and to access new structures represent a challenge as very often the cyclopropanes are difficult to access and do not have the required reactivity.…”

Asymmetric cyclopropanation of conjugated cyanosulfones using a novel cupreine organocatalyst: rapid access to δ3-amino acids

“…1 It is also of synthetic use, especially if functionalised with the correct arrangement of electron--donating and electron--withdrawing groups, as it can then undergo a variety of nucleophilic, electrophilic or pericyclic reactions. 2 If the cyclopropane is asymmetric in nature, then the products of these transformations also tend to be enantiopure. As a result, routes to enantiopure cyclopropanes have been extensively studied, 3 particularly with respect to the Simmons--Smith reaction, 4 and transition metal catalysed reactions using carbene intermediates.…”