Synthesis of Tetraarylallenes via Palladium-Catalyzed Addition-Elimination Reactions of 1,1,3-Triaryl-2-propyn-1-ols with Aryl Iodides
作者:Ming-Jung Wu、Li-Mei Wei、Li-Lan Wei、Wen-Bin Pan
DOI:10.1055/s-2005-872228
日期:——
The palladium-catalyzed reactions of tert-propargylic alcohols with aryl iodides afforded tetraarylallenes in good yields. This reaction involves: (1) oxidative addition of the aryl iodide to Pd(0); (2) arylpalladium intermediate coordination to the carbon-carbon triple bond of the 1,1,3-triaryl-2-propyn-1-ol and subsequent regioselective insertion of the alkynol to form β-hydroxyvinylpalladium species; and (3) β-elimination to produce the tetraarylallenes. Generally, the best results are obtained by employing 5 mol% of Pd(TFA)2, 10 mol% of PPh3, two equivalents of aryl iodide and five equivalents of Et3N in MeCN.
[(3-Dimethylamino)propyl]dimethylaluminum: A Convenient Reagent for Methylation and Ethynylation of Carbonyl Compounds
作者:Wael Baidossi、Ayelet Rosenfeld、Brigit C. Wassermann、Stefan Schutte、Herbert Schumann、Jochanan Blum
DOI:10.1055/s-1996-4334
日期:1996.9
At 60-80°C the title compound methylates a variety of mono- and diketones. Aromatic aldehydes undergo simple methylation by the reagent only after initial treatment with an equivalent amount of AlCl3. Upon reaction of Me2Al(CH2)3NMe2 with terminal acetylenes the aluminum complex is converted into a carbonyl-alkynylation reagent.
3-Alkenylation or 3-Alkylation of Indole with Propargylic Alcohols: Construction of 3,4-Dihydrocyclopenta[<i>b</i>]indole and 1,4-Dihydrocyclopenta[<i>b</i>]indole in the Presence of Different Catalysts
作者:Li Zhang、Yuanxun Zhu、Guangwei Yin、Ping Lu、Yanguang Wang
DOI:10.1021/jo300339a
日期:2012.11.2
3-alkylation of indole with propargylic alcohols could be efficiently controlled by the catalyst. In the presence of triflic acid, 3-alkenylation of indole occurred and a 3,4-dihydrocyclopenta[b]indole skeleton was effectively constructed in moderate to excellent yields via a cascade process. In the presence of Cu(OTf)2, 3-alkylation of indole resulted in the formation of 3-propargylic indole, which could
催化剂可以有效地控制吲哚与炔丙醇的3-烯基化或3-烷基化。在三氟甲磺酸存在下,吲哚发生3-烯基化反应,并通过级联法以中等至极好的收率有效地构建了3,4-二氢环戊[ b ]吲哚骨架。在铜(OTF)的存在下2,吲哚的3-烷基化导致形成3-丙炔吲哚,其可进一步转化为2-碘-1,4-二氢环戊二烯并[ b ]吲哚在存在Ñ -碘代琥珀酰亚胺和三氟化硼醚化物。与吲哚的3-链烯基化或3-烷基化有关的可能机制,以及它们延伸至3,4-二氢环戊五烯的形成[ b提出并讨论了]吲哚或1,4-二氢环戊[ b ]吲哚。
Ca(II)-Catalyzed Cascade Reaction of Tryptamines with Propargylic Alcohols: Temperature-Driven Ring Opening and Closing via the Allene Migration Pathway for the Synthesis of Pyrrolo[1,2-<i>a</i>]indoles
作者:Ashok Kale、Su Jeong Kwon、Joohan Lee、Jae Kyun Lee、Kyeong Lee
DOI:10.1021/acs.orglett.3c04357
日期:2024.2.16
temperature-dependent cascade of reactions between tryptamines and propargylicalcohols was developed to achieve selective formation of pyrroloindoline and pyrrolo[1,2-a]indole heterocycles by Ca(II) catalysis. The cascade consists of electrophilic addition of allene at the C3 carbon of indole followed by intramolecular cyclization at 60 °C to yield pyrroloindolines. Furthermore, simultaneous 1,2-allene
开发了色胺和炔丙醇之间的温度依赖性级联反应,以通过 Ca(II) 催化选择性形成吡咯并吲哚啉和吡咯并[1,2- a ]吲哚杂环。该级联包括在吲哚的 C3 碳上进行丙二烯的亲电加成,然后在 60 °C 下进行分子内环化,生成吡咯并吲哚啉。此外,同时进行1,2-丙二烯迁移和吡咯烷开环,然后在回流温度下通过C-N键形成进行分子内环化,以获得吡咯并[1,2- a ]吲哚支架。该方案的优点是底物范围广泛、反应过程干净、可扩展性以及良好至优异的产率。
Willemart, Annales de Chimie (Cachan, France), 1929, vol. <10> 12, p. 363