Development of a Titanocene-Catalyzed Enyne Cyclization/Isocyanide Insertion Reaction
摘要:
The first early transition metal-catalyzed enyne cyclization reaction is described. The system converts enyne substrates to bicyclic iminocyclopentenes through the use of 10 mol % of Cp(2)Ti(PMe(3))(2) in the presence of a silyl cyanide. Subsequent hydrolysis produces the corresponding bicyclic cyclopentenones in good overall yield. The cyclization reaction is tolerant of polar functional groups such as ethers, amines, and esters and is diastereoselective with certain chiral enyne substrates.
The reaction of enynes with aldehydes in the presence of a catalytic amount of [RhCl(cod)](2)/dppp results in the Pauson-Khand-typereaction without the use of gaseous carbon monoxide to give bicyclic cyclopentenones in high yields (14 examples). Aldehydes serve as a source of carbon monoxide, and their carbonyl moiety is transferred to enynes, resulting in the formation of the carbonylated products
在催化量的 [RhCl(cod)](2)/dppp 存在下,烯炔与醛的反应会导致 Pauson-Khand 型反应,而无需使用气态一氧化碳,以高产率得到双环环戊烯酮 (14例子)。醛作为一氧化碳的来源,它们的羰基部分被转移到烯炔,导致形成羰基化产物。该反应代表了 CO 转移羰基化的第一个例子。
Rhodium-Catalyzed Pauson-Khand-Type Reaction Using Alcohol as a Source of Carbon Monoxide
作者:Ji Hoon Park、Yoonhee Cho、Young Keun Chung
DOI:10.1002/anie.201001246
日期:2010.7.12
cyclopentenones have been synthesized from enynes in alcohol in the presence of a rhodium catalyst through a newly developed auto‐tandem catalytic reaction. This process combines three mechanistically distinctive reactions—an oxidation of alcohols, a decarbonylation of aldehydes, and a carbonylative [2+2+1] cycloaddition (see scheme; dppp=propane‐l,3‐diylbis(diphenylphosphane)).
Intramolecular Pauson–Khand reaction catalyzed by oxime-derived palladacycles
作者:Xue-Rui Wang、Fu-Hua Lu、Yang Song、Zhong-Lin Lu
DOI:10.1016/j.tetlet.2011.11.106
日期:2012.2
Oxime-derived palladacycles were successfully applied as a novel class of catalysts in the intramolecularPauson–Khandreactions. Allylpropargyl ethers and allylpropargyl amines can be efficiently converted to the cyclopentenone products with good to excellent yields.
Utilization of Aldoses as a Carbonyl Source in Cyclocarbonylation of Enynes
作者:Keiichi Ikeda、Tsumoru Morimoto、Kiyomi Kakiuchi
DOI:10.1021/jo1012288
日期:2010.9.17
The reaction of enynes with acetyl-masked aldoses in the presence of a rhodium(I) catalyst resulted in cyclocarbonylation, thus avoiding the direct use of carbon monoxide, to afford bicyclic cyclopentenones. In rhodium catalysis, aldoses serve as a carbon monoxide equivalent by donating their carbonyl moieties on the acyclic aldehyde form to enynes. A variety of aldoses, including d-glucose, d-mannose
Catalytic cyclocarbonylation reactions using a glyceraldehyde derivative as a carbonyl source are described. The rhodium(I)-catalyzed reaction of enynes with glyceraldehyde acetonide gave bicyclic cyclopentenones as the products. This presents an interesting use of a sugar alcohol derived carbon resource as well as a convenient procedure for the cyclocarbonylation of enynes. rhodium - cyclocarbonylation