Stereoselective Synthesis of 1,3-Dienes from Propargylic Alcohols by LiAlH4/AlCl3
摘要:
Herein we report that LiAlH4/AlCl3 is a very efficient reagent for the reductive dehydration of aryl propargylic alcohols in tetrahydrofuran solvent at reflux to give 1,3-dienes with good yields and high E selection. The reaction conditions are mild and easy to operate, and a variety of aryl functional groups, such as bromo, fluoro, butyl, and methoxyl groups, are tolerated. With our protocol, useful (E,E)-1,3-dienes can be synthesized. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) to view the free supplemental file.
An Approach to the Selenobromination of Aryl(thienyl)alkynes: Access to 3-Bromobenzo[<i>b</i>]selenophenes and Selenophenothiophenes
作者:Edgars Paegle、Sergey Belyakov、Pavel Arsenyan
DOI:10.1002/ejoc.201402095
日期:2014.6
A novel approach for the cyclization of arylalkynes with selenium(IV) bromide prepared in situ has been elaborated. The use of an alkene additive as a bromine scavenger provides a convenient synthetic pathway for the synthesis of a wide variety of 3-bromobenzo[b]selenophenes. Reactions can be performed open to air without the use of moisture-sensitive reagents, anhydrous solvents, or an inert atmosphere
详细阐述了一种用原位制备的溴化硒 (IV) 环化芳炔的新方法。使用烯烃添加剂作为溴清除剂为合成各种 3-溴苯并 [b] 硒酚提供了方便的合成途径。反应可以在空气中进行,无需使用对湿气敏感的试剂、无水溶剂或惰性气氛。乙炔基噻吩的硒溴化作用已用于制备硒酚[3,2-b]-和硒酚[2,3-b]噻吩。代表性衍生物的分子结构已通过 X 射线晶体学分析得到证实。
Highly Efficient Synthesis of Multi-Substituted Allenes from Propargyl Acetates and Organoaluminum Reagents Mediated by Palladium
作者:Qinghan Li、Zhen Zhang、Xuebei Shao、Gang Zhang、Xinying Li
DOI:10.1055/s-0036-1588177
日期:2017.8
The process was simple and easily performed, which offers an efficient method to synthesize the multi-substituted allene derivatives. A simple and mild catalytic SN2′ substitution reaction of propargylacetates with organoaluminum reagents is reported. The SN2′ substitution reaction of propargylacetates with organoaluminum reagentsmediated by Pd(PhP3)2Cl2 (1 mol%)/PPh3 (2 mol%)/K2CO3 in tetrahydrofuran
摘要 一种简单和温和的催化小号Ñ报道与有机铝试剂炔丙基乙酸酯的2'取代反应。Pd(PhP 3)2 Cl 2(1 mol%)/ PPh 3(2 mol%)/ K 2 CO 3在四氢呋喃中于60°C介导的乙酸丙炔酯与有机铝试剂的S N 2'取代反应3– 4小时以高产率(高达99%)以良好的产率(高达94%)提供了相应的多取代的烯。该方法简单易行,为合成多取代的丙二烯衍生物提供了一种有效的方法。 一种简单和温和的催化小号Ñ报道与有机铝试剂炔丙基乙酸酯的2'取代反应。Pd(PhP 3)2 Cl 2(1 mol%)/ PPh 3(2 mol%)/ K 2 CO 3在四氢呋喃中于60°C介导的乙酸丙炔酯与有机铝试剂的S N 2'取代反应3– 4小时以高产率(高达99%)以良好的产率(高达94%)提供了相应的多取代的烯。该方法简单易行,为合成多取代的丙二烯衍生物提供了一种有效的方法。
Palladium-Catalyzed One-Pot Consecutive Amination and Sonogashira Coupling for Selective Synthesis of 2-Alkynylanilines
efficient catalytic approach to the synthesis of N,N-dialkyl-2-alkynylanilines was developed by using Pd-catalyzed norbornene-mediated three-component reactions of haloarenes, alkoxyamines (RO-NR2), and alkynes. The procedure forms one CN bond and one CC bond efficiently in a one-pot manner from readily available starting materials. A number of 2-alkynylanilines with a broad range of functional groups
Propargyl alcohols as alkyne sources: Synthesis of heterocyclic compounds under microwave irradiation
作者:Karu Ramesh、Gedu Satyanarayana
DOI:10.1016/j.jorganchem.2020.121350
日期:2020.9
Fused heterocyclic compounds with alkyne substituent, have been achieved using a domino microwave-assisted [Pd]-catalysis. Interestingly, tert-propargyl alcohols underwent a selective degradative β-carbon cleavage and served as masked alkynyl equivalents, in water as the sole reaction medium. Dihydrobenzofurans, indolines, and oxindoles have been accomplished using this dual C–C bond-forming strategy
Easy synthesis of imidazo[1,5-<i>a</i>]indol-3-ones through Rh(<scp>iii</scp>)-catalyzed C–H allenylation/annulation
作者:Bin Zhu、Zhenyu Yao、Lang Huang、Xiuling Cui
DOI:10.1039/d1cc04359e
日期:——
A highly efficient and regioselective synthesis of imidazo[1,5-a]indol-3-ones has been developed via a sequential C–H allenylation/annulation startingfrom easily available N-methoxycarbamoyl indoles and propargyl alcohols, in which the propargyl alcohols served as a C1 synthon. This strategy displays excellent regioselectivity, high atom economy and tolerates a broad substrate scope.
咪唑并[1,5 - a ] indol -3-ones的高效和区域选择性合成已通过连续的C - H烯丙基化/环化从易于获得的N-甲氧基氨基甲酰基吲哚和炔丙醇开始,其中炔丙醇用作作为 C1 合成子。该策略显示出优异的区域选择性、高原子经济性和广泛的底物范围。