Raghu Moluguri, Grover Jagdeep, Ramasastry S S V
Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Manuali PO, S. A. S. Nagar, Punjab, 140306, India.
Chemistry. 2016 Dec 19;22(51):18316-18321. doi: 10.1002/chem.201604562. Epub 2016 Oct 31.
A new approach for the cyclopenta[b]annulation of heteroarenes through metal-free and directing-group-free γ'[C(sp )-H] functionalization and intramolecular hydroalkylation of ynones has been developed. In an unprecedented event, nucleophilic addition of an organophosphine to the designed ynones triggers γ'[C(sp )-H] functionalization, leading to the formation of heteroaryl-based ortho-quinodimethane (oQDM) intermediates that undergo carbocyclization to provide cyclopentannulated heteroarenes in good yields and excellent stereoselectivities. Deuterium-labeling experiments substantiated the proposed reaction mechanism as well as the speculated epimerization.
通过无金属且无导向基团的γ'[C(sp )-H]官能化以及烯炔酮的分子内氢烷基化反应，开发了一种用于杂芳烃环戊并[b]环化的新方法。在一个前所未有的过程中，有机膦对设计的烯炔酮进行亲核加成引发γ'[C(sp )-H]官能化，导致形成基于杂芳基的邻醌二甲烷（oQDM）中间体，该中间体进行碳环化反应，以良好的产率和优异的立体选择性提供环戊并环化的杂芳烃。氘标记实验证实了所提出的反应机理以及推测的差向异构化。
