Treatment of internal alkynes with sodium methoxide in the presence of Pd(OAc)2 and PPh3 in methanol for 48 h gave the reduction products, alkenes or alkanes in good chemical yields. This reaction proceeds through a palladium methanolate complex, followed by β-hydride elimination and reductive elimination.
Regio- and Stereoselective Electrophilic Cyclization Approach for the Protecting-Group-Free Synthesis of Alkaloids Lennoxamine, Chilenine, Fumaridine, 8-Oxypseudoplamatine, and 2-<i>O</i>-(Methyloxy)fagaronine
作者:Tuanli Yao、Zhen Guo、Xiujuan Liang、Lihan Qi
DOI:10.1021/acs.joc.8b02154
日期:2018.11.2
protecting-group-free synthesis of alkaloids lennoxamine, chilenine, fumaridine, 8-oxypseudoplamatine, and 2-O-(methyloxy)fagaronine is reported. The core isoindolin-1-one and isoquinolin-1-one structures were built by a silver-catalyzed regio- and stereoselective cyclization of methyl 2-alkynylbenzimidates. The regioselectivity of cyclization was achieved by utilizing the intrinsic functionality of alkaloids.
Palladium-catalyzed coupling of aryl iodides with 2-alkynylbenzonitriles
作者:Li-Mei Wei、Chi-Fong Lin、Ming-Jung Wu
DOI:10.1016/s0040-4039(99)02254-6
日期:2000.2
The reaction of 2-(2-phenylethynyl)benzonitrile (1a) with aryl iodides, in the presence of Pd(PPh3)(4) and NaOCH3 in CH3OH, at refluxing temperature for 24 h, gave 3-diarylmethylideneisoindoles 3a-d in 18-56% yields. When 2-(1-hexynyl)benzonitrile (1b) was employed in this reaction, isoquinolines 2a-c were obtained in 29-34% yields and isoindoles 3e-g were obtained in 12-25% yields, respectively. Reaction of 2-ethynylbenzonitrile (1c) with 2.5 equiv, of iodobenzene for 48 h gave 3a in 45% yield along with the monocoupled adduct 3h in 6% yield. (C) 2000 Elsevier Science Ltd. All rights reserved.
Highly stereoselective synthesis of (Z)-3-methoxy-1-methyleneisoindoles via DMAP catalyzed cyclization of methyl 2-alkynylbenzimidates
作者:Tuanli Yao、Xiujuan Liang、Zhen Guo、Dong Yang
DOI:10.1016/j.tet.2019.04.036
日期:2019.6
A DMAP (4-dimethylaminopyridine) catalyzed cyclization of methyl 2-alkynylbenzimidates has been developed, which affords 3-methoxy-1-methyleneisoindoles with excellent Z-stereoselectivity under mild and transition-metal-free conditions. The (Z)-3-methoxy-1-methyleneisoindole products can be converted to corresponding 3-amino-1-methyleneisoindoles, 3-methoxy-isoindoles, 3-methyleneisoindolinones and