Scope of Ru(II)-Catalyzed Synthesis of Pyridines from Alkynes and Nitriles
作者:Jesús A. Varela、Luis Castedo、Carlos Saá
DOI:10.1021/jo035050b
日期:2003.10.1
Pyridines can be efficiently synthesized by Ru(II)-catalyzed [2 + 2 + 2] cycloaddition of 1,6-diynes to alpha,omega-dinitriles or electron-deficient nitriles or by Ru(II)-catalyzed [2 + 2 + 2] cocyclization of electron-deficient alkynes and electron-deficient nitriles. The reactions with dinitriles seem likely to proceed via ruthenacyclopentadiene intermediates and the reactions with electron-poor
Air-tolerant C–C bond formation via organometallic ruthenium catalysis: diverse catalytic pathways involving (C5Me5)Ru or (C5H5)Ru are robust to molecular oxygen
carbon pronucleophiles, various [2+2+2] cycloadditions, and addition of a diazocompound to an alkyne are shown to proceed in the presence of air. Notably diverse catalytic manifolds remain supported under conditions generally regarded as prohibitive. Building on rare reports from the literature we show that a range of organometallic transformations based on reaction intermediates derived from (C5Me5)Ru
碳原子亲核试剂的钌催化取代,各种[2 + 2 + 2]环加成反应以及重氮化合物向炔烃的加成反应均在空气存在下进行。值得注意的是,各种催化歧管在通常被认为是禁止的条件下仍保持支撑。基于文献的稀有报道,我们表明基于衍生自(C 5 Me 5)Ru或(C 5 H 5)Ru部分的反应中间体的一系列有机金属转化是与空气相容的。
Cationic Rhodium(I)/Modified-BINAP Catalyzed [2+2+2] Cycloaddition of Alkynes with Nitriles
作者:Ken Tanaka、Nanami Suzuki、Goushi Nishida
DOI:10.1002/ejoc.200600347
日期:2006.9
Cationicrhodium(I)/modified-BINAP complexes catalyze a chemo- and regioselective [2+2+2] cycloaddition of a wide variety of alkynes and nitriles leading to highly functionalized pyridines under mild reaction conditions. The asymmetric variant of this reaction, enantioselective desymmetrization of substituted malononitriles, also proceeded to give enantio-enriched bicyclic pyridines which possess a