One-pot synthesis of a natural product inspired pyrrolocoumarine compound collection by means of an intramolecular 1,3-dipolar cycloaddition as key step
作者:Srinivasa Rao Vidadala、Herbert Waldmann
DOI:10.1016/j.tetlet.2015.01.021
日期:2015.6
A general, sequential and efficient one-pot synthesis of natural product inspired chromeno[3,4-b]pyrrol-4(3H)-ones is described. The one-pot reaction sequence consists of N-Boc deprotection of a N-substituted Boc-glycine O-aryl ester embodying an ortho-alkyne substituent, azomethine ylide generation with an aldehyde, subsequent intramolecular 1,3-dipolarcycloaddition with the alkyne followed by oxidative
描述了由天然产物激发的chromeno [3,4- b ]吡咯-4(3 H)-ones的一般,顺序和有效的一锅合成。一锅法反应序列由体现邻炔烃取代基的N-取代Boc-甘氨酸O-芳基酯的N-Boc脱保护,乙醛生成甲亚胺基叶立德,随后与炔烃分子内进行1,3-偶极环加成通过氧化芳香化。这种合成方法使人们可以高效地获得一系列高度取代的各种吡咯香豆香豆素。
One-pot synthesis of 2-aryl-3-alkoxycarbonyl chromones through a cascade Lewis acid-catalyzed aldehyde olefination/oxa-Michael addition/oxidation
作者:Ningning Wang、Shuying Cai、Chao Zhou、Ping Lu、Yanguang Wang
DOI:10.1016/j.tet.2012.11.008
日期:2013.1
were effectively constructed from aryl aldehydes and 3-(2-(methoxymethoxy)phenyl)propiolates via a cascade Lewis acid catalyzed phenol ether deprotection/aldehyde olefination/intramolecular oxa-Michael addition reaction, and a sequential oxidation. This four-step reaction could be conducted in one-pot with high atom efficiency.
In the presence of 5 mol% Pd(OAc)2, 1 equiv. of norbornene, and K2CO3, the reaction of 4-iodo-2-quinolones with tertiary o-bromobenzylic alcohols produced the desired benzopyran-fused 2-quinolones in moderate to high yields. A Catellani-type mechanism involving vinylic C–H cleavage is proposed based on the results of control experiments and density functional theory calculations.
在5mol%Pd(OAc)2的存在下,1当量。降冰片烯和K 2 CO 3的作用下,4-碘-2-喹诺酮与叔邻溴苄醇的反应以中等至高产率产生了所需的苯并吡喃稠合的2-喹诺酮。基于控制实验和密度泛函理论计算的结果,提出了一种涉及乙烯基C–H裂解的Catellani型机理。
Steric hindrance is a key factor in the coupling reaction of (acyloxy) alkyl-α-halides with phenols to make a new promoiety for prodrugs
作者:Hui Ouyang、Ronald T Borchardt、Teruna J Siahaan
DOI:10.1016/s0040-4039(01)02241-9
日期:2002.1
(Acyloxy) alkyl-α-halides were conjugated with phenols in acetone in the presence of cesium carbonate to give (acyloxy) alkyl-α-ethers of phenols. Sterichindrance is a key factor governing this reaction and greater sterichindrance favors the alkylation product over the acylation product.
Copper-Catalyzed Three-Component Synthesis of 2-Iminodihydrocoumarins and 2-Iminocoumarins
作者:Yang Shen、Sunliang Cui、Jing Wang、Xiaopeng Chen、Ping Lu、Yanguang Wang
DOI:10.1002/adsc.200900890
日期:——
AbstractAn efficient synthesis of N‐sulfonyl‐substituted 2‐imino‐3,4‐dihydrocoumarins and 2‐iminocoumarins via a copper‐catalyzed multicomponent reaction of sulfonyl azides with terminal alkynes and β‐(ortho‐hydroxyphenyl)‐α,β‐unsaturated ketones or ortho‐hydroxyphenylpropiolates has been developed. The cascade process involves trapping the keteimine by a nucleophilic addition and an intramolecular Michael addition. This methodology could well be extended to the concise synthesis of the polysubstituted piperidine scaffold.