通过微波辅助聚磷酸乙酯(PPE)促进的ω-硫代酰胺醇的闭环反应,开发了一种高效且通用的合成2-取代的噻唑啉和5,6-二氢-4 H -1,3-噻嗪的方法。环化反应涉及S N 2型机理,具有反应时间短,产率高和可预测的立体化学结果的优点。无环前体是通过改进的二酰化-硫磺化-皂化顺序,从市售的ω-氨基醇中以高收率制备的。整个过程无金属且操作简单。
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。
Iron-Catalyzed Anti-Markovnikov Hydroamination and Hydroamidation of Allylic Alcohols
作者:Wei Ma、Xiaohui Zhang、Juan Fan、Yuxuan Liu、Weijun Tang、Dong Xue、Chaoqun Li、Jianliang Xiao、Chao Wang
DOI:10.1021/jacs.9b05221
日期:2019.8.28
nonpolar solvent, features exclusive anti-Markovnikov selectivity, broad substrate scope (>70 examples), and good functional group tolerance. The reaction could be performed at gram scale and applied to the synthesis of drug molecules and heterocyclic compounds. When chiral substrates are used, the stereochemistry and enantiomeric excess are retained. Further application of the chemistry is seen in the
Development and Applications of Transesterification Reactions Catalyzed by N-Heterocyclic Olefins
作者:Marcus Blümel、Janina-Miriam Noy、Dieter Enders、Martina H. Stenzel、Thanh V. Nguyen
DOI:10.1021/acs.orglett.6b00835
日期:2016.5.6
A novel method to utilize N-heterocyclic olefins (NHOs), the alkylidene derivatives of N-heterocycic carbenes, as organocatalysts to promote transesterification reactions has been developed. Because of their strong Brønsted/Lewis basicity, NHOs can enhance the nucleophilicity of alcohols for their acylation reactions with carboxylic esters. This transformation can be employed in industrially relevant
Sharma, S. D.; Mehra, Usha; Kaur, Sukhjinder, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1984, vol. 23, # 9, p. 857 - 859