A rapid approach for the copper, amine, and ligand-free Sonogashira coupling of 4-methyl-7-nonafluorobutylsulfonyloxy coumarins under microwave irradiation

作者：Joy M Nibin; Bodke Yadav D^*; Khader K K Abdul; Sajith Ayyiliyath M

来源：Tetrahedron Letters, 2014, 55(15): 2355-2361.

DOI：10.1016/j.tetlet.2014.02.094

• Coumarin
• Nonaflate
• Sonogashira coupling
• Microwave

A rapid, efficient, and reliable access for the synthesis of an assortment of 4-methyl-7-allcyl/aryl/heteroaryl alkynyl coumarins has been developed by the copper, amine, and ligand-free Sonogashira cross-coupling reaction of 4-methyl-7-nonafluorobutylsulfonyloxy coumarin with various terminal alkynes under microwave irradiation. In the presence of a suitable catalyst, base, and solvent, the coupling reaction proceeded smoothly to give the diaryl alkynes in satisfactory to exceptional yields. Nonaflates coupled more efficiently than the corresponding triflates which yielded the detriflated product as well as the hydrolyzed product as competing side products along with the required product. The utilization of TBAF center dot 3H(2)O as a mild base as well as a solvating agent was the key for success of the reaction.

• 出版日期2014-4-9