Guntreddi Tirumaleswararao, Shankar Majji, Kommu Nagarjuna, Sahoo Akhila K
School of Chemistry , University of Hyderabad , Hyderabad , Telangana 500046 , India.
Advanced Center of Research in High Energy Materials (ACRHEM) , University of Hyderabad , Hyderabad , Telangana 500046 , India.
J Org Chem. 2019 Oct 18;84(20):13033-13044. doi: 10.1021/acs.joc.9b01878. Epub 2019 Aug 23.
A ruthenium (Ru)-catalyzed double annulation of easily accessible -methoxybenzamide derivatives with unactivated alkynes for the synthesis of unusual 6,6-fused pyranoisoquinolines is described. Both -C-H bonds of arenes and the N- and O-moieties of -methoxybenzamides are involved in the construction of four [(C-C)-(C-N) and (C-C)-(C-O)] bonds in one step under single catalytic conditions. The unsymmetrical annulation of -methoxybenzamides with two distinct alkynes is also demonstrated. The oxidizable directing group -methoxyamine (NHOMe) assists the unsymmetrical double annulations of arenes [that use both N- and O-heteroatoms] in a single operation. This synthetic method features excellent substrate scope and tolerates a wide range of functional groups. Peripheral modification of pyranoisoquinolines for the construction of complex heterocyclic compounds is also demonstrated.
描述了一种钌（Ru）催化的易获得的α-甲氧基苯甲酰胺衍生物与未活化炔烃的双环化反应，用于合成不寻常的6,6-稠合吡喃异喹啉。在单一催化条件下，芳烃的两个C-H键以及α-甲氧基苯甲酰胺的N和O部分一步参与构建四个[（C-C）-（C-N）和（C-C）-（C-O）]键。还展示了α-甲氧基苯甲酰胺与两种不同炔烃的不对称环化反应。可氧化的导向基团甲氧基胺（NHOMe）在一次操作中协助芳烃[使用N和O杂原子]的不对称双环化反应。这种合成方法具有出色的底物范围，并且能耐受多种官能团。还展示了对吡喃异喹啉进行外围修饰以构建复杂杂环化合物的方法。
