ABSTRACT Donor–acceptor cyclopropanes (DACs) have emerged as powerful multifunctional synthons in cyclization reactions, harnessing their strained three‐membered ring and polarized electronic system to enable stereoselective ring‐opening/cyclization cascades with nucleophiles. This reactivity facilitates the construction of diverse cyclic architectures, including carbocycles, heterocycles, and bridged systems, with applications in asymmetric synthesis via chiral transition‐metal catalysts (e.g., Pd, Cu, Zn, and Ni complexes). Sequential ring‐opening and intramolecular cyclization steps, driven by intrinsic ring strain and electron‐withdrawing/donating substituents, allow for the transformation of DACs into two‐atom, three‐atom, and four‐atom synthons for complex ring formation. This review systematically explores their synthetic applications in cycloaddition/annulation reactions as two‐atom, three‐atom, and four‐atom synthons, providing mechanistic insights and scope evaluations to guide the design of novel cyclization strategies. The versatility of DACs in constructing cyclic frameworks highlights their potential in natural product synthesis and the development of bioactive molecules, offering valuable guidance for synthetic chemists.
Zhang et al. (Fri,) studied this question.