Efficient stereoselective synthesis of benzoxazines via copper-catalyzed three-component coupling reactions
作者:Xiaobing Xu、Linfeng Liang、Jun Liu、Jingyu Yang、Lugen Mai、Yanzhong Li
DOI:10.1016/j.tetlet.2008.10.080
日期:2009.1
A convenient one-potsynthesis of 1,4-benzoxazines viathree-componentcoupling and subsequent O-cyclization is reported. The present reaction provides an efficient protocol to functionalized 1,4-benzoxazine derivatives in good to high yields from aldehydes, amines and alkynes. Furthermore, the O-annulation process is completely regio- and stereoselective, only the six-membered rings and its Z-isomers
A Highly Stereoselective Synthesis of (Z)-N-Aryl(alkyl)-2-arylidine-2,3-dihydro-1,4-benzoxazines through Palladium Catalyzed Reactions
作者:Gopeswar Chaudhuri
DOI:10.1055/s-1998-1917
日期:1998.11
Palladium-Catalyzed Heteroannulation Leading to Heterocyclic Structures with Two Heteroatoms: A Highly Regio- and Stereoselective Synthesis of (<i>Z</i>)-4-Alkyl-2-alkyl(aryl)idene-3,4-dihydro-2<i>H</i>-1,4-benzoxazines and (<i>Z</i>)-3-Alkyl(aryl)idene-4-tosyl-3,4-dihydro-2<i>H</i>-1,4-benzoxazines
作者:Nitya G. Kundu、Gopeswar Chaudhuri、Anup Upadhyay
DOI:10.1021/jo000826j
日期:2001.1.1
triethylamine at room temperature to yield 2-[N-alkyl(benzyl)-N-(3-aryl-prop-2'-ynyl)]-aminophenyl tosylates 8 in extremely good yields (72-96%). The latter could then be cyclized with KOH in ethanol-water to Z-9 in a highlyregio- and stereoselective manner. Similarly, palladium-copper-catalyzed reaction of 2-(prop-2'-ynyloxy)aniline (21) with aryl iodides 7 led to 22-26 which after tosylation and cyclization