The Cyclopropyl Group as a Neglected Donor in Donor–Acceptor Cyclopropane Chemistry.

D–A cyclopropanes bearing a simple cyclopropyl group as donor are shown to undergo a variety of [3+n]-cycloaddition reactions (n = 2–4). This behavior contrasts sharply with that of common D–A cyclopropanes with aliphatic donors. Kinetic experiments demonstrate that, in terms of donor ability, the cyclopropyl substituent lies between electron-rich and electron-neutral aryl donors. [ABSTRACT FROM AUTHOR]