Department of Chemistry, Indian Institute of Science Education and Research Bhopal , Bhauri, Bhopal 462066, India.
Org Lett. 2014 Nov 7;16(21):5580-3. doi: 10.1021/ol502614n. Epub 2014 Oct 22.
An unprecedented strategy for the synthesis of enantioenriched 1-substituted 1,3-dihydroisobenzofurans via an enantioselective oxa-Michael reaction of o-alkoxyboronate containing chalcone (II) has been accomplished employing cinchona alkaloid based squaramide bifunctional organocatalyst in the presence of proton source. The corresponding alkoxyboronate intermediates have been readily prepared in situ from o-formyl chalcones using neutral borane as hydride source and a tertiary amine moiety which is a counterpart of the catalyst.
通过使用基于金鸡纳生物碱的螺二酰胺双功能有机催化剂，并在质子源的存在下，实现了通过对含邻烷氧基硼酸酯查尔酮（II）的对映选择性氧杂迈克尔加成反应来合成对映体富集的 1-取代 1,3-二氢异苯并呋喃的前所未有的策略。相应的烷氧基硼酸酯中间体可以通过使用中性硼烷作为氢源和催化剂的对应物的叔胺部分，从邻甲酰基查尔酮原位制备。
