Sequential One‐Pot Coupling Reactions of Diiodobenzenes, Propiolic Acid, and Aryl Halides for the Synthesis of Diarylalkynyl Arenes

Abstract

Diiodobenzenes were employed in palladiumcatalyzed one-pot sequential reactions with propiolic acid and aryl halides to provide the corresponding diarylalkynyl benzenes. The combination of Pd(PPh 3) 4 (10 mol %) and DBU (5.0 equiv) gave optimal results in the sequence. Reactions with 1,2-diiodobenzene gave higher yields than those utilizing 1,3-and 1,4-diiodobenzenes. Furthermore, benzenes bearing electron-donating substituents gave higher yields than those with electron-withdrawing substituents.

Transition metal-catalyzed alkynylation reactions via alkynyl carbon–carbon bond cleavage

“…The sequential coupling reaction with Pd(PPh 3 ) 4 as the catalyst and DBU as the base could be carried out in one-pot manner (Scheme 3). 13…”

“…The sequential coupling reac- tion with Pd(PPh 3 ) 4 as the catalyst and DBU as the base could be carried out in one-pot manner (Scheme 3). 13 To further expand the substrate scope for the decarboxylative coupling, Lee and co-workers developed palladium-catalyzed decarboxylative gem-selective addition of alkynyl carboxylic acids to terminal alkynes (Scheme 4). 14 Alkynyl carboxylic acids could react with propargyl alcohols and terminal alkynes respectively to afford the enyne products.…”