halogenated cycloadducts via cyanation using copper and SNArreaction provides substituted selenopyridines with good yields. A novel synthetic method for the preparation of selenopyridine derivatives, involving a [2+2+2] cycloaddition of α,ω-diynes and selenocyanates that is catalyzed by a ruthenium complex is described. This mild and straightforward reaction allows access to a wide range of selenopyridines
作为有机合成中的特殊主题钌的一部分出版 抽象的 描述了一种制备硒吡啶吡啶衍生物的新颖合成方法,该方法涉及由钌配合物催化的α,ω-二炔和硒氰酸酯的[2 + 2 + 2]环加成。使用二氯甲烷或二氯乙烷作为溶剂,在50或80°C下,这种温和而直接的反应可以以高收率和优异的区域选择性获得各种硒吡啶。使用铜和S N Ar反应通过氰化作用将卤代环加合物进行后官能化,可提供具有良好收率的取代硒基吡啶。 描述了一种制备硒吡啶吡啶衍生物的新颖合成方法,该方法涉及由钌配合物催化的α,ω-二炔和硒氰酸酯的[2 + 2 + 2]环加成。使用二氯甲烷或二氯乙烷作为溶剂,在50或80°C下,这种温和而直接的反应可以以高收率和优异的区域选择性获得各种硒吡啶。使用铜和S N Ar反应通过氰化作用将卤代环加合物进行后官能化,可提供具有良好收率的取代硒基吡啶。
Palladium(0)-Catalyzed Intermolecular Carbocyclization of (1,<i>n</i>)-Diynes and Bromophenols: An Efficient Route to Tricyclic Scaffolds
A novel palladium(0)‐catalyzed dearomative cyclization reaction of bromophenols with (1,n)‐diynes has been developed for building two new types of tricyclic architectures containing a quaternary carbon center. This method employs inexpensive bromophenols, and easily accessible tethered diynes. It exhibits a broad substrate scope and tolerates various functional groups. Preliminary results with commercially
Iron(<scp>ii</scp>)-catalysed [2+2+2] cycloaddition for pyridine ring construction
作者:Vincent Richard、Mélinda Ipouck、Delphine S. Mérel、Sylvain Gaillard、Richard J. Whitby、Bernhard Witulski、Jean-Luc Renaud
DOI:10.1039/c3cc47700b
日期:——
We report a new, simple and air-stable iron(II) complex pre-catalyst for the synthesis of substituted pyridines via a [2+2+2] cycloaddition between diynes and nitrile derivatives.
A method for the synthesis of phosphabenzenes under iron catalysis is described. Thus, the FeI2‐catalyzed [2+2+2] cycloaddition of diynes with phosphaalkynes in m‐xylene gave a variety of phosphabenzenes in good to high yields (up to 87 % yield).
The use of N‐(p‐chlorophenyl)methylbenzoxazole‐2‐thione as a sulfur‐atom donor enables the catalytic [2+2+1] cycloaddition of diynes in wet DMF at 80 °C when open to air, thus affording diverse fused thiophenes with good yields and wide functional‐group compatibility. A plausible mechanism, involving a cationic ruthenacycle intermediate, was also proposed on the basis of several control experiments