Dihydrobenzoxazines and tetrahydroquinoxalines by a tandem reduction-reductive amination reaction
作者:Richard A. Bunce、Derrick M. Herron、Lu Y. Hale
DOI:10.1002/jhet.5570400611
日期:2003.11
A tandemreduction-reductiveaminationreaction has been applied to the synthesis of 3,4-dihydro-2H-1,4-benzoxazines and 1-acetyl-1,2,3,4-tetrahydroquinoxalines. The nitroketones required for the benzoxazine ring closures were prepared by (A) alkylation of the anion derived from 2-nitrophenol with an allylic halide or (B) nucleophilic aromatic substitution of an allylic alkoxide on 2-fluoro-1-nitrobenzene
串联还原-还原胺化反应已用于合成3,4-二氢-2 H -1,4-苯并恶嗪和1-乙酰基-1,2,3,4-四氢喹喔啉。苯并恶嗪环闭合所需要的硝基酮是通过(A)用烯丙基卤化物将2-硝基苯酚衍生的阴离子烷基化,或(B)在2-氟-1-硝基苯上进行烯丙基醇盐的亲核芳族取代,然后进行臭氧分解来制备的。喹喔啉的前体是通过将2-硝基乙酰苯胺的阴离子与烯丙基卤化物烷基化,然后进行臭氧分解来制备的。然后在甲醇中使用5%钯碳催化硝基酮的加氢反应,然后通过还原-还原胺化顺序得到目标杂环。该ñ通过在还原之前添加5-10当量的甲醛水溶液,可以轻松制备两个环系统的α-甲基衍生物。通过色谱法纯化后,高产率地分离出二氢苯并恶嗪。以相似的方式分离四氢喹喔啉,并在两个氮原子上具有不同的官能度。
BECKWITH A. L. J.; MEIJS G. F., J. ORG. CHEM., 52,(1987) N 10, 1922-1930
作者:BECKWITH A. L. J.、 MEIJS G. F.
DOI:——
日期:——
Iododediazoniation of arenediazonium salts accompanied by aryl radical ring closure
作者:Athelstan L. J. Beckwith、Gordon F. Meijs
DOI:10.1021/jo00386a007
日期:1987.5
In Tandem Enantioselective Intramolecular Heck‐Matsuda Reactions directly from Anilines
作者:Tomaz Henrique Duarte Chorro、Edson Leonardo Scarpa de Souza、Otto Daolio Köster、Ellen Christine Polo、Rafaela Costa Carmona、Vitor Hugo Menezes da Silva、João Marcos Batista Junior、Carlos Roque Duarte Correia
DOI:10.1002/adsc.202201313
日期:2023.1.24
yields up to 91% and enantiomeric ratios up to 97:3, including quaternary stereocenters. The in-tandem processes from anilines were compared to conventional Heck-Matsuda reactions using pre-synthesized aryldiazonium salts. With few exceptions, the reactions starting directly from the anilines afforded better overall yields and enantioselectivity, demonstrating the efficiency of the method.