环酰亚胺,2-苄基-5,6-二氢-4 H -1,3-恶嗪1a,1b,1c,1d,1e,1f与乙炔基二羧酸二甲酯2,三乙烯三羧酸三甲酯4或二甲基-2-甲基的环加成反应(甲氧基亚甲基)丙二酸二乙酯6,得到新的稠合杂环化合物,例如甲基(6-氧代-3,4-二氢-2 ħ吡咯并[2,1- b ] -1,3-恶嗪-7-亚基)乙酸酯3a中,3b,3c,3d,3e,3f(71-79%),二甲基-2-(6-氧代-3,4,6,7-四氢-2- ħ吡咯并[2,1- b ] -1,3-恶嗪-7-基)丙二酸酯5B,5c,5d,5e,5f(43–71%)或甲基6-氧代-3,4-二氢-2 H,6 H-吡啶基[ 2,1- b ] -1,3-恶嗪-7-羧酸盐分别为7a,7b,7c,7d,7e,7f(32–59%)。在这些反应中1a,1b,1c,1d,1e,1f(环状亚氨酸酯类,iminoethers)充当其N,C -tauto
A simple synthesis of Δ2-oxazines, Δ2-oxazines, Δ2-thiazolines and 2-substituted benzoxazoles
作者:Helmut Vorbrüggen、Konrad Krolikiewicz
DOI:10.1016/0040-4020(93)80021-k
日期:1993.1
Carboxylic acids react readily at O°→+24°C with amino alcohols, amino mercaptans and o-aminophenols in the presence of triphenylphosphine- or tributylphosphine dichloride (generated from the reaction of the phosphines with hexachloroethane or CCl4) and triethylamine in acetonitrile to form the corresponding Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and 2-substituted benzoxazoles in reaction step in
Microwave-Assisted Synthesis of 2-Aryl-2-oxazolines, 5,6-Dihydro-4<i>H</i>-1,3-oxazines, and 4,5,6,7-Tetrahydro-1,3-oxazepines
作者:María C. Mollo、Liliana R. Orelli
DOI:10.1021/acs.orglett.6b03122
日期:2016.12.2
general procedure for the synthesis of 5- to 7-membered cyclic iminoethers by microwave-assisted cyclization of ω-amido alcohols promoted by polyphosphoric acid (PPA) esters is presented. 2-Aryl-2-oxazolines and 5,6-dihydro-4H-1,3-oxazines were efficiently prepared using ethyl polyphosphate/CHCl3. Trimethylsilyl polyphosphate in solvent-free conditions allowed for the synthesis of hitherto-unreported
提出了通过微波辅助多磷酸(PPA)酯促进的ω-氨基醇的环化反应合成5至7元环亚氨基醚的第一个通用程序。使用聚磷酸乙酯/ CHCl 3有效地制备了2-芳基-2-恶唑啉和5,6-二氢-4 H -1,3-恶嗪。在无溶剂条件下,多磷酸三甲基甲硅烷基酯可合成迄今未报道的4,5,6,7-四氢-1,3-氧杂氮杂pine。该方法具有良好的收率和优异的收率,并且反应时间短。在手性底物中研究了PPA酯的反应机理和作用。
CuCl-catalyzed radical cyclisation of N-α-perchloroacyl-ketene-N,S-acetals: a new way to prepare disubstituted maleic anhydrides
作者:Andrea Cornia、Fulvia Felluga、Vincenzo Frenna、Franco Ghelfi、Andrew F. Parsons、Mariella Pattarozzi、Fabrizio Roncaglia、Domenico Spinelli
DOI:10.1016/j.tet.2012.04.117
日期:2012.7
The copper-catalyzed radical cyclization (RC) of N-α-perchloroacyl cyclic ketene-N,X(X=O, NR, S)-acetals was studied. While the RC of N-acyl ketene-N,O-acetals was unsuccessful, the 5-endo cyclization of the other ketene acetals provided much better results, with the following order of cyclization efficiency: hexa-atomic cyclic ketene-N,NR-acetals
A simple synthesis of Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and Δ2-imidazolines
作者:Helmut Vorbrüggen、Konrad Krolikiewicz
DOI:10.1016/s0040-4039(01)93017-5
日期:1981.1
acids react with amino alcohols, amino mercaptans or diamines in the presence of triphenylphosphine, CCl4 and tert. bases to afford in 50–75% yield the corresponding Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and Δ2-imidazolines.
One-Step Conversion of Aldehydes to Oxazolines and 5,6-Dihydro-4<i>H</i>-1,3-oxazines Using 1,2- and 1,3-Azido Alcohols
作者:Jennifer G. Badiang、Jeffrey Aubé
DOI:10.1021/jo9521256
日期:1996.1.1
The reactions of 1,2- and 1,3-hydroxy azides with aldehydes under acidic conditions were examined. A variety of Lewis acids were examined, of which BF3 . OEt(2) was found the most convenient. Trimethylsilyl ether derivatives of the alcohols could also be reacted using trimethylsilyl triflate as the promoter. Twenty-five examples that proceed in moderate to quantitative yields are reported.