在此,描述了一种由 1-苯基-1,2-丙二酮-2-肟氨基硫脲官能化聚苯乙烯树脂负载的 Pd(0) 配合物催化的酰氯和末端炔烃的无铜和无溶剂偶联反应的高效方法。酰氯很容易与末端炔烃偶联,在室温和有氧条件下,在 Et 3 N 中存在低催化剂负载量(1 mol% Pd)的情况下,可产生良好或高产率。离心后,负载型催化剂可以回收和重复使用多次,活性仅略有下降。
Synthesis of Spiro-lactams and Polysubstituted Pyrroles via Ceric Ammonium Nitrate-Mediated Oxidative Cyclization of <i>N</i>-Furan-2-ylmethyl-β<i>-</i>Enaminones
Spiro-lactams and polysubstituted pyrroles were synthesized by reactions of furfurylamines with ynones followed by oxidation. Specifically, the protocol involved in situ generation of N-furan-2-ylmethyl-β-enaminones and their subsequent oxidation by ceric ammonium nitrate (6 equiv for spiro-lactam formation, 3 equiv for pyrrole formation). This useful dearomatizing oxidation, which likely proceeds via a
Michael Addition-Lactonization Reaction of Electron-Deficient Alkynes with N-(Diphenylmethylene)glycinates: An Efficient Synthesis of 3-Amino-2-pyrone Derivatives
作者:Tao Lu、Qing-Fa Zhou、Yong Zhu、Wei-Fang Tang
DOI:10.1055/s-0029-1217098
日期:2010.1
approach is based on the Michael addition of N-(diphenylmethylene)glycinates to various alkynyl ketones, followed by lactonization using 10 mol% sodium hydroxide as catalyst. Aromatic and aliphatic alkynyl ketones were converted into the corresponding 3-amino-2-pyrone derivatives in moderate to high yields. When methyl propiolate was submitted to the reaction, α,β-dehydroamino acids were formed in good
Cycloaddition of Alkynyl Ketones with <i>N</i>-Tosylimines Catalyzed by Bu<sub>3</sub>P and DMAP: Synthesis of Highly Functionalized Pyrrolidines and Azetidines
Cycloadditions of alkynyl ketones with N-tosylimines catalyzed by Lewis bases to synthesize azetidines and pyrrolidines were systematically described. In the reaction of alkynyl ketones with N-tosylimines catalyzed by Bu3P at room temperature in toluene, highly functionalized pyrrolidines were formed in good to excellent yields. When DMAP was used in place of Bu3P as catalyst to facilitate the cycloaddition, completely substituted azetidines were produced in moderate to good yields in CH2Cl2. Both cyclization reactions proceeded smoothly with complete stereoselectivity. The scope and limitations of these cycloadditon reactions were also investigated.
Palladium-catalyzed cross-carbonylation of aryl iodides and 1-aryl-2-alkyn-1-ones