Transmetalation of Z-Telluroenynes: Stereoselective Synthesis of Z-Enynols and Their Application in Palladium-Catalyzed Cyclization

Abstract

The synthesis of various Z-enynols via reaction of vinyllithium intermediate with aldehydes and ketones is described. The subsequent cyclization of a wide variety of Z-enynols afforded substituted furans and dihydrofurans with high regioselectivity under mild reaction conditions.

Synthesis of 2,5-Disubstituted 3-Iodofurans via Palladium-Catalyzed Coupling and Iodocyclization of Terminal Alkynes

“…Recently, several studies have focused on the development of metal-catalyzed transformation, including the cyclization of alkynyl, allenyl, cyclopropyl, and cyclopropenyl ketone derivatives. Alternative strategies involve the cyclization of functionalized oxirane, alkynols, ( Z )-2-en-4-yn-1-ols, substituted propargyl vinyl ethers, and others …”

Carbon Nitride in Energy Conversion and Storage: Recent Advances and Future Prospects

“…The Sonogashira coupling of the iodo product E ‐3 a with phenyacetylene in the presence of [PdCl 2 (PPh 3 ) 2 ] and CuI proceeded to give the enynol 7 in 73 % yield 10a. The cyclization reaction of enynol 7 with [PdCl 2 (PPh 3 ) 2 ] in THF at reflux afforded furans 8 and 9 in 18 % and 36 % yields, respectively 18. Although it took a long reaction time, the transformation of the iodo product E ‐5 a directly afforded the furan 10 in 49 % yield (Scheme ).…”

Transition Metal-Mediated Synthesis of Monocyclic Aromatic Heterocycles

“…126 The reaction proceeds well with various substrates and gives the corresponding furans in high yields (Scheme 66). 127 The synthesis of furans via the Pd-catalyzed cycloisomerization of ( Z )-2-en-4-yn-1-ols was also studied by Cadierno et al 128 and Zeni et al 129 …”