One-Pot Synthesis of Symmetrical and Unsymmetrical Bisarylethynes by a Modification of the Sonogashira Coupling Reaction

Abstract

A modification of the Sonogoshira coupling reaction employing an amidine base and a substoichiometric amount of water generates symmetrical and unsymmetrical bisarylethynylenes in one pot through in situ deprotection of trimethylsilylethynylene-added intermediates.

Rhodium catalyzed reaction of internal alkynes with organoborons under CO atmosphere: a product tunable reaction

“…8 The alkynes 1s,t were synthesized as described elsewhere. 9 Arylboroxines were synthesized by azeotropic removal of water from the refluxing benzene solution of arylboronic acids. 10 The products were analyzed by GC and GC-MS (Varian Star 3400CX/Saturn 2000 or HP 6890/5973N) and isolated by column chromatography.…”

C(sp2)‐C(sp) and C(sp)‐C(sp) Coupling Reactions Catalyzed by Oxime‐Derived Palladacycles

“…The crude reaction mixture was extracted with water and EtOAc (3 Â 15 mL). The organic phases were dried, evaporated (15 mm Hg) and the resulting crude was purified by flash chromatography (hexane/EtOAc) affording the corresponding 7,9-hexadecadiyne (13a); [19] (19), 65 (27), 63 (26), 62 (11), 55 (27), 53 (22), 51 (24).…”

“…[21] Finally, Grieco et al have used the system PdCl 2 (PPh 3 ) 2 /CuI in the presence of an amidine such as 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) as base, for the one-pot synthesis of symmetrical and unsymmetrical bisarylethynes employing TMSA under aqueous conditions. [22] Acetylenic homocoupling of terminal alkynes [4] (Glaser reaction), is an atom economic and straightforward method for the synthesis of conjugated diynes, polyynes and acetylenic arrays. These derivatives are finding increasing applications as key structural elements of new materials with unusual electrical and optical properties, and are encountered in numerous natural and biologically active compounds.…”

Synthesis and electropolymerization of a series of 2,2′-(ortho-carboranyl)bisthiophenes

“…The Sonogashira cross-coupling reaction of commercially available 2-iodothiophene and 2-[(trimethylsilyl)ethynyl]-thiophene, deprotected in situ in the presence of 1,8-diazabicycloundec-7-ene (DBU), using bis(triphenylphosphine)-palladium(II) dichloride and copper(I) iodide as catalysts, produced 2,2'-ethylenedithiophene in 87% yield. [50] Reaction of 2,2'-ethylenedithiophene with decaborane and diethyl sulfide gave the key precursor 2,2'-o-carboranyldithiophene 9 in 35% yield. [22,23] Bromination of the two α-positions of 2,2'-carboranyldithiophene 9 was accomplished using 6 equiv of N-bromosuccinimide (NBS) in chloroform and acetic acid (1:1), at 130 o C overnight, producing the dibrominated product 10a in 76% yield, [51] as shown in Scheme 1.…”