Palladium-catalyzed, ligand-free S N 2’ substitution reactions of organoaluminum with propargyl acetates for the synthesis of multi-substituted allenes
作者:Xuebei Shao、Chang Wen、Gang Zhang、Kangping Cao、Ling Wu、Qinghan Li
DOI:10.1016/j.jorganchem.2018.06.020
日期:2018.9
We describe a convenient method for the synthesis of multi-substituted allenes from SN2′ substitution reactions organoaluminum with propargyl acetates: The SN2′ substitution reaction of organoaluminum (0.4 mmol) with propargyl acetates (0.5 mmol) mediated by PdCl2(dppf) (1 mol%) at 60 °C in THF without ligand could produce multi-substituted allenes in moderate to good yields (up to 98%) and high selectivities
Coupling of arylboronic acids with benzyl halides or mesylates without adding transition metal catalysts
作者:Guojiao Wu、Shuai Xu、Yifan Deng、Chaoqiang Wu、Xia Zhao、Wenzhi Ji、Yan Zhang、Jianbo Wang
DOI:10.1016/j.tet.2016.10.031
日期:2016.12
We report herein a transition-metal-free coupling reaction of arylboronic acids with benzyl halides and mesylates for the construction of C(sp2)C(sp3) bonds. A unique feature of this coupling reaction is the formation regioisomers in some cases. Mechanistic studies suggest that this reaction may proceed via an unprecedented Friedel–Crafts-type reactionpathway under base conditions with the assistance
Simple and efficient nickel-catalyzed cross-coupling reaction of alkynylalanes with benzylic and aryl bromides
作者:Deepak B. Biradar、Han-Mou Gau
DOI:10.1039/c1cc14206b
日期:——
efficient and simple coupling reactions of benzylic and arylbromides with aluminium acetylide catalyzed by NiCl(2)(PPh(3))(2) are reported. The coupling reactions proceed at room temperature employing 4 mol% catalyst, affording coupling products in excellent yields of up to 95% in short reaction times. The system worked efficiently with aryl and heterocyclic bromides as well.
Propargylation of 1,3-dicarbonyl compounds catalyzed by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and sodium nitrite in the presence of molecular oxygen and formic acid
作者:Dongping Cheng、Xiayi Zhou、Xiaoliang Xu、Jizhong Yan
DOI:10.1039/c6ra06704b
日期:——
Catalyzed by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and sodium nitrite, the coupling reaction of 1,3-diarylpropynes and 1,3-dicarbonyl compounds using molecularoxygen as a terminal oxidation was developed. The reaction was promoted dramatically in...