Transition metal-free diastereospecific synthesis of (Z)-2-arylidene-2,3-dihydrobenzo[b][1,4]dioxines by reaction of (Z)-1,2-dibromo-3-aryl-2-propenes with catechols
作者:Szymon P. Rekowski、Aabid A. Wani、Jürgen Conrad、Prasad V. Bharatam、Wolfgang Frey、Uwe Beifuss
DOI:10.1016/j.tet.2020.131482
日期:2020.10
A transition metal-free, diastereospecific reaction between substituted (Z)-1,2-dibromo-3-phenyl-2-propenes and substitutedcatechols using Cs2CO3 as a base at 140 °C for 18 h delivers exclusively substituted (Z)-2-arylidene-2,3-dihydrobenzo[b][1,4]dioxines in yields up to 89%. Experiments as well as quantum chemical calculations support the assumption that the one pot transformation proceeds as an
在140°C下以Cs 2 CO 3为碱在取代的(Z)-1,2-二溴-3-苯基-2-丙烯与取代的邻苯二酚之间进行的无过渡金属非对映异构反应可产生仅被取代的(Z)-2-亚芳基-2,3-二氢苯并[ b ] [1,4]二恶英的产率高达89%。实验以及量子化学计算均支持以下假设:一锅转化以分子间O-烯丙基化/分子内O-乙烯基化的方式进行。
The reaction of substituted ethyl α-bromocinnamates with tetrabutyl ammonium fluoride
作者:Yan Liang、Ying Peng Zhang、Wei Yu
DOI:10.1016/j.cclet.2012.05.015
日期:2012.7
-bromocinnamates with tetrabutyl ammonium fluoride (TBAF) was influenced largely by the position of the substituent at the phenylring. While the substrates without an ortho substituent at the phenylring were transformed to the corresponding β -fluoro ethyl cinnamates under the reaction conditions, the presence of an ortho substituent only resulted in the formation of ethyl 3-phenylpropiolate derivatives
One-pot process in phosphonium-iodonium ylides: nucleophilic substitution and the Wittig reaction
作者:E. D. Matveeva、T. A. Podrugina、A. S. Pavlova、A. V. Mironov、N. S. Zefirov
DOI:10.1007/s11172-008-0061-4
日期:2008.2
nucleophilic substitution in mixed phosphonium-iodonium ylides was investigated. The iodonium group is replaced by such S-containing nucleophiles as the thiocyanate anion or thiourea, as well as by halide ions. The structure of the reaction product with the thiocyanate ion was established by X-ray diffraction. A one-pot process involving the nucleophilic substitution and the Wittig reaction was developed
研究了混合鏻-碘鎓叶立德中的亲核取代。碘鎓基团被诸如硫氰酸根阴离子或硫脲之类的含硫亲核试剂以及卤离子取代。通过 X 射线衍射确定了与硫氰酸根离子反应产物的结构。开发了涉及亲核取代和 Wittig 反应的一锅法。
A facile synthesis of 3-aryl pyroglutamic acid. Facile synthesis of baclofen and chlorpheg
A facile synthesis of 3-aryl pyroglutamic acids via stepwise [3+2] annulation and desulfonated hydrolysis is reported. Base-induced coupling/cyclization reactions of alpha-sulfonylacetamide with various beta-functional groups of (Z)-2-bromoacrylates yielded three contiguous chiral centers on the polysubstituted pyroglutamates system with trans-trans orientation in a one-pot synthesis. This facile strategy was used to synthesize amino acid derivatives baclofen and chlorpheg. (C) 2003 Published by Elsevier Science Ltd.
4-PYRIDYL- UND 2,4-PYRIMIDINYL-SUBSTITUIERTE PYRROLDERIVATE UND IHRE ANWENDUNG IN DER PHARMAZIE