Regio- and diastereoselective dearomatizations of <i>N</i>-alkyl activated azaarenes: the maximization of the reactive sites
作者:Hong-Jie Miao、Le-Le Wang、Hua-Bin Han、Yong-De Zhao、Qi-Lin Wang、Zhan-Wei Bu
DOI:10.1039/c9sc04880d
日期:——
An unprecedented base-promoted multi-component one-pot dearomatization of N-alkyl activated azaarenes was developed, which enabled the synthesis of complex and diverse bridged cyclic polycycles with multiple stereocenters in a highly regio- and diastereoselective manner. Besides, we realized the step-controlled dearomative bi- and trifunctionalization of quinolinium salts. These transformations not
Diastereoselective trifunctionalization of pyridinium salts to access structurally crowded azaheteropolycycles
作者:Zhaohui Cui、Kuan Zhang、Lijie Gu、Zhanwei Bu、Junwei Zhao、Qilin Wang
DOI:10.1039/d1cc03478b
日期:——
A highly diastereoselective dearomative trifunctionalization of pyridinium salts with multifunctional o-hydroxy aromatic azomethine ylides has been established to assemble challenging and architecturally crowded fused pentacycles.
Synthesis of 3,5-diacyl-4-phenyl-1,4-dihydropyridines
作者:M.-Lluïsa Bennasar、Cecília Juan、Joan Bosch
DOI:10.1016/s0040-4039(98)02084-x
日期:1998.12
via a regio- and chemoselective addition of Ph2Cu(CN)Li2 to β-substituted N-alkylpyridinium salts, followed by acylation of the intermediate 1,4-dihydropyridines with trichloroacetic anhydride and subsequent haloform-type reaction. A similar sequence using an N-silylpyridinium salt and PhMgBr allows the preparation of the corresponding N-unsubstituted dihydropyridines.
Regioselective Dearomatization of
<i>N</i>
‐Alkylquinolinium and Pyridinium Salts under Morita‐Baylis‐Hillman Conditions
作者:Abhishek Pareek、Marcin Kalek
DOI:10.1002/adsc.202200429
日期:2022.8.16
activating the electron-poor olefin as well as a base. The dearomatization occurs regioselectively at the C-2 position, delivering a broad range of α-(1,2-dihydroquinolin-2-yl)vinyl esters, ketones, and sulfones. The scope of the transformation has also been extended to N-alkylpyridinium salts. For this class of substrates a presence of at least moderately electron-withdrawing substituent in the ring is necessary