A rhodium-catalyzed hydroformylation of alkynes with formic acid was developed. The method provides α,β-unsaturated aldehydes in high yield and E-selectivity without the need to handle toxic CO gas.
A Highly Efficient and Recyclable Pd(Pph<sub>3</sub>)<sub>4</sub>/Peg-400 System for Stille Cross-Coupling Reactions of Organostannanes with Aryl Bromides
作者:Xue Huang、Fang Yao、Ting Wei、Mingzhong Cai
DOI:10.3184/174751917x15045169836226
日期:2017.9
Pd(PPh3)4 in PEG-400 is shown to be a highly efficient catalyst for the Stille cross-coupling reactions of various organotin compounds with arylbromides. The reaction could be conducted at 80 °C using NaOAc as base, yielding a variety of biaryls, alkynes and alkenes in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and the Pd(PPh3)4/PEG-400
A highly efficient PtO2/PTSA catalyst system for the hydration of a wide array of alkynes was developed. This method proved to be compatible with a large range of functional groups and the ketone products were obtained in high yields. The scope of this methodology was also extended to the synthesis of 3-aryl-isochromenones, -indoles and -benzofurans.
Remote ether groups-directed regioselective and chemoselective cycloaddition of azides and alkynes
作者:Xuelun Duan、Nan Zheng、Ming Li、Xinhao Sun、Zhuye Lin、Pan Qiu、Wangze Song
DOI:10.1016/j.cclet.2021.05.037
日期:2021.12
5-regioselectivities and excellent chemoselectivities. Ether group could coordinate with iridium catalyst by lone-pair electron at a distance (up to four σ bonds) away from alkyne to control the regioselectivity by weak coordination effect. The cycloaddition reaction chemoselectively occurred at the propargyl ether moiety of diyne to give unique fully substituted 4-alkynyl-triazole.
A decarboxylative approach for regioselective hydroarylation of alkynes
作者:Jing Zhang、Ruja Shrestha、John F. Hartwig、Pinjing Zhao
DOI:10.1038/nchem.2602
日期:2016.12
group that activates one of several aromatic C–H bonds. Here we report a new catalytic method for regioselective alkyne hydroarylation with benzoicacid derivatives during which the carboxylate functionality directs the alkyne to the ortho-C–H bond with elimination in situ to form a vinylarene product. The decarboxylation stage of this tandem sequence is envisioned to proceed with the assistance of