Asymmetric Dearomative Cascade Multiple Functionalizations of Activated <i>N</i>-Alkylpyridinium and <i>N</i>-Alkylquinolinium Salts
作者:Xue Song、Ru-Jie Yan、Wei Du、Ying-Chun Chen
DOI:10.1021/acs.orglett.0c02828
日期:2020.10.2
An enantioselectivecascadereaction of N-alkylpyridinium and -quinolinium salts with o-hydroxybenzylideneacetones to access fused polyheterocycles through cross dienamine-mediated addition followed by trapping of the dearomatized enamine-type intermediates and aminal formation has been developed. A cascade assembly of N-benzyl-4-methylpyridinium salt and cyclic 2,4-dienones is further disclosed to
Compounds of formula (I)
and pharmaceutically acceptable salts thereof are agonists at the beta-2 adrenoceptor. They are useful as feed additives for livestock animals.
化学式为(I)的化合物及其药学上可接受的盐是β-2肾上腺素受体激动剂。它们可用作家畜饲料添加剂。
Dually activated Michael-Michael-acetalization cascade: facile and highly diastereoselective construction of tetrahydro-6-hydroxyl-6H-benzo[c]chromen-9-one polycyclic scaffold
作者:Jian Liu、Sai-Shuai Wen、Jing Wang、Jun-An Xiao、Shao-Jie Huang、Hua Yang
DOI:10.1016/j.tet.2015.05.014
日期:2015.7
A Michael-Michael-acetalization cascade between 4-(2-hydroxyphenyl)but-3-en-2-ones and alpha,beta-unsaturated aldehydes via a novel dual activation mode promoted by pyrrolidine was successfully established. Consequently, various novel tetrahydro-6-hydroxyl-6H-benzo[c]chromen-9-one derivatives were prepared in excellent diastereoselectivities and moderate to good yields. Further diverse modification of the resulting tricyclic scaffolds provided a facile pathway to achieve a variety of tetrahydro-6-hydroxyl-6H-benzo[c]chromen-9-one analogs. (C) 2015 Elsevier Ltd. All rights reserved.
Construction of Hydrodibenzo[<i>b</i>,<i>d</i>]furan Frameworks from Morita–Baylis–Hillman Carbonates of Isatins and <i>o</i>-Hydroxy Enones via Palladium and Brønsted Base Relay Catalysis