Uracil-Cu(i) catalyst: allylation of cyclopropanols with Morita–Baylis–Hillman alcohols under water-tolerant conditions

Abstract

Inspired by the high affinity of copper with DNA and RNA, a uracil-copper catalytic system was developed to promote ring-opening allylation of cyclopropanols with allylic alcohols under water-tolerant conditions. A new C–OH bond-breaking model can well resolve the trade-off between the need for acidic activators for C(allyl)–OH bond cleavage and the demand for strong basic conditions for generating homoenolates. Therefore, Morita–Baylis–Hillman alcohols, rather than their pre-activated versions, could be incorporated directly into dehydrative cross-coupling with cyclopropanols delivering water as the only by-product. A variety of functionalized δ,ε-unsaturated ketones were obtained in good-to-high yield with high E-selectivity.