Department of Organic Chemistry II, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
Instituto de Síntesis QuímicayCatálisis Homogénea (ISQH), Universidad de Zaragoza CSIC, 50009, Zaragoza, Spain.
Chemistry. 2018 Jun 21;24(35):8764-8768. doi: 10.1002/chem.201801434. Epub 2018 May 22.
In this work, carboxylic acids, which are typically regarded as poor nucleophiles, are demonstrated to be competent reagents to promote the ring-opening of formylcyclopropanes after activation of the latter through iminium ion formation. Under optimized reaction conditions, a variety of γ-acyloxy-substituted aldehydes can be obtained in high yields and enantioselectivities through the desymmetrization of substituted meso-formylcyclopropanes in the presence of a chiral secondary amine as catalyst.
在这项工作中，羧酸通常被认为是较差的亲核试剂，但我们证明，通过亚胺离子的形成对后者进行活化后，羧酸能够作为试剂促进甲酰基环丙烷的开环反应。在优化的反应条件下，在手性仲胺作为催化剂的存在下，通过取代的内消旋甲酰基环丙烷的去对称化，可以以高产率和对映选择性得到各种γ-烷氧基取代的醛。
