Access to Chiral Tetrahydroquinazolines/1,3-Benzoxazines via Iridium-Catalyzed Asymmetric [4 + 2] Cycloaddition
作者:Shengbiao Tang、Zhangru Cheng、Peng Zhang、Ying Shao、Jiangtao Sun
DOI:10.1021/acs.orglett.3c01004
日期:2023.5.26
An iridium-catalyzed asymmetric [4 + 2] cycloaddition of 1,3,5-triazinanes with 2-(1-hydroxyallyl)anilines/2-(1-hydroxyallyl)phenols has been developed, providing a straightforward and efficient approach to a wide range of tetrahydroquinazolines in good yields and excellent enantioselectivities (up to >99% ee). Typically, chiral 1,3-benzoxazines, which are challenging substrates in asymmetric [4 +
Synthesis of (Z)-1,2-dihydro-1-tosylbenzo[b]azepin-3-ones by two-step, one-pot gold-catalyzed tandem heterocyclization/Petasis–Ferrier rearrangement of 2-(N-(prop-2-ynyl)-N-tosylamino)benzaldehydes
作者:Ella Min Ling Sze、Ming Joo Koh、Yen Min Tjia、Weidong Rao、Philip Wai Hong Chan
DOI:10.1016/j.tet.2013.04.069
日期:2013.7
A two-step, one-pot synthetic method that relies on gold(I)-catalyzed tandem heterocyclization/Petasis-Ferrier rearrangement and Bronsted acid-assisted debenzoxylation of 2-(N-(prop-2-ynyl)-N-tosylamino)benzaldehydes to prepare (2)-1,2-dihydro-1-tosylbenzo[b]azepin-3-ones efficiently is reported. The reactions proceed rapidly under mild and operationally straightforward conditions for a wide variety of aldehyde substrates containing electron-withdrawing, electron-donating, and sterically demanding functional groups and afforded the corresponding benzo-fused azaheterocyclic products in moderate to excellent yields. (C) 2013 Elsevier Ltd. All rights reserved.