Gold(III)-Catalyzed Regioselective Oxidation/Cycloisomerization of Diynes: An Approach to Fused Furan Derivatives
作者:Jian Li、Hong-Wen Xing、Fang Yang、Zi-Sheng Chen、Kegong Ji
DOI:10.1021/acs.orglett.8b01915
日期:2018.8.3
The first gold(III)-catalyzed regioselective oxidation/cycloisomerization of diynes 1 with pyridine N-oxide as the oxidant was developed, providing a range of synthetically valuable and useful fused furan derivatives 3 in moderate to good yields. Control experiments and the confirmation structure of minor products 5 suggest that this chemistry was a concerted gold(III)-catalyzed oxidation/SN2′-type
开发了第一金(III)催化的以吡啶N-氧化物为氧化剂的二炔1的区域选择性氧化/环异构化,以中等至良好的产率提供了一系列具有合成价值的有用的熔融呋喃衍生物3。对照实验和次要产物的确认结构5表明,这种化学是协调一致的金(III)催化的氧化/ S Ñ 2'-型加成/环化经由β-金vinyloxypyridinium中间和推定的乙烯基阳离子中间过程。
Cobalt-Catalyzed Intramolecular [2 + 2 + 2] Cocyclotrimerization of Nitrilediynes: An Efficient Route to Tetra- and Pentacyclic Pyridine Derivatives
we wish to report the intramolecular [2 + 2 + 2] cocyclotrimerization of nitrilediynes catalyzed by the CoI2(dppe)/Zn system at 80 degrees C in CH3CN. Under these reaction conditions, various highly substituted nitrilediynes having steric conjunction at the alpha and beta positions to a nitrile group and a bulkier substitution at the terminal carbon of alkyne undergo [2 + 2 + 2] cocylotrimerization