Studies on Tetrahydrofuran‐Based Highly O‐Functionalized Alkynes: Applications to Synthesis of Tetrahydrofuranyl‐Polyynes and C‐Nucleoside Analogues

Abstract

The enantiomerically pure tetrahydrofuranylalkynes 17-20 were synthesized by using various methods. By utilizing these alkynes, an efficient CuI-catalysed sp-sp carbon homocoupling protocol in dry DMF without other additives (like amine or base, phosphane and palladium catalyst) has been developed. The method has been applied to the synthesis of symmetrical butadiynyl (32-37), octatetraynyl (47) and dodecahexaynyl (49) polyynes. The unsymmetrically substi-

1-Iodobuta-1,3-diynes in Copper-Catalyzed Azide–Alkyne Cycloaddition: A One-Step Route to 4-Ethynyl-5-iodo-1,2,3-triazoles

“…Since the discovery, CuAAC has been also expanded for the regioselective synthesis of 5-iodo­(bromo)-1,4-disubstituted 1,2,3-triazoles starting from iodo­(bromo)­alkynes − (Scheme A) and 1-substituted 4-ethynyl-1,2,3-triazoles from either terminal diacetylenes − or trialkylsilylbuta-1,3-diynes with a one-pot desylilation − (Scheme D).…”