Efficient copper-free Pd(OAc)2/Ruphos-catalyzed Sonogashira coupling in the preparation of 3′-hydroxycorfin and gymnopalynes A analogues

• DOI: 10.1016/j.tetlet.2014.11.059
• Publication Date: 2014-11-22T15:57:05Z
• Authors: Changalaraya Dasa...; Yadavalli Suneel ...; Fazlur-Rahman Naw...; Euh Duck Jeong; Eun Hyuk Chung
• Keywords: Sonogashira coupling; Tetrahydrofuran; Aqueous medium

Abstract An efficient method involving copper-free Pd(OAc) 2 /Ruphos-catalyzed Sonogashira coupling strategy for a variety of 3-alkynyl isochromen-1-ones has been developed. Sonogashira coupling in the presence of catalytic system—Pd(OAc) 2 /Ruphos, Et 3 N base, and tetrahydrofuran solvent under aqueous and room temperature conditions, provided novel 3-(alkynyl)-1H-isochromen-1-ones in excellent yields. The methodology has also been extended toward natural isochromen-1-one–3′-hydroxycorfin and gymnopalynes A analogues.