Cu-Catalyzed Fe-Driven C_sp–C_sp and C_sp–C_sp2 Cross-Coupling: An Access to 1,3-Diynes and 1,3-Enynes

Abstract

An efficient Csp-Csp cross-coupling of alkynyl bromide and pinacol ester of alkynyl boronic acid catalyzed by CuFe2O4 nanoparticles has been accomplished in dimethyl carbonate to produce unsymmetric 1,3-diynes. This protocol is also extended for the Csp-Csp2 coupling of alkynyl bromide and alkenyl boronic acid to provide conjugated 1,3-enynes. The aliphatic, aromatic, and heteroaromatic alkynes couple with various substituted alkynyl/alkenyl boronates/boronic acids by this procedure to furnish a library of 1,3-diynes and enynes in high yields. The catalyst was easily separated by an external magnet and recycled 10 times.

Tailored Palladium Catalysts for Selective Synthesis of Conjugated Enynes by Monocarbonylation of 1,3‐Diynes

“…[3] Traditional approaches to this class of compounds include olefination of propargyl aldehydes, [4] dehydration of propargyl alcohols, [5] and mainly metalcatalyzed cross-addition of alkynes. [6] In addition, the transition-metal-catalyzed Sonogashira coupling reaction of alkynes with vinyl halides, [7] and related cross-coupling reactions between terminal organometallic alkynes and alkenes, [8] provide prevalent methodologies for their synthesis. Despite all these remarkable progresses, there is continuous interest in the development of a more efficient and general synthesis of functionalized 1,3-enynes from readily available starting materials.…”

Synthesis and Reactivity of Copper and Copper Containing Magnetically Separable Catalysts

“…However, a minor amount (2–5 %) of homocoupled products was also generated which can be easily removed during the purification process. Using the same procedure biologically relevant conjugated 1,3‐enynes 102 can also be synthesized in impressive yields by the Csp−Csp 2 cross‐coupling of alkynyl bromides and alkenyl boronic acids [103] . The reaction proceededwith complete retention of stereochemistry,thus,the coupling of ( E )‐styrenylwith vinyl boronic acids gave the ( E )‐1,3‐enynes.…”

“…[102] The group of Ranu described the applications of commercially available CuFe 2 O 4 nanoparticle as a catalyst for unsymmetric1,3-diynes synthesisin the presence of dimethyl carbonate (DMC) as a green reaction medium andCs 2 CO 3 as base. [103] The CspÀ Csp cross-coupling of a series of diversely substituted (alkyl, cycloalkyl, aryl, and heteroaryl) alkynyl bromides with various substituted alkynyl boronic esters provided a library of unsymmetric 1,3-diynesin high yields. However, a minor amount (2-5 %) of homocoupled products was also generated which can be easily removed during the purification process.…”

“…The conjugated 1,3‐diynes are useful building blocks in pharmaceuticals, polymers, natural products, industrial and optical materials [102] . The group of Ranu described the applications of commercially available CuFe 2 O 4 nanoparticle as a catalyst for unsymmetric1,3‐diynes synthesisin the presence of dimethyl carbonate (DMC) as a green reaction medium andCs 2 CO 3 as base [103] . The Csp−Csp cross‐coupling of a series of diversely substituted (alkyl, cycloalkyl, aryl, and heteroaryl) alkynyl bromides with various substituted alkynyl boronic esters provided a library of unsymmetric 1,3‐diynesin high yields.…”

Tailored Palladium Catalysts for Selective Synthesis of Conjugated Enynes by Monocarbonylation of 1,3‐Diynes

“…[3] Tr aditional approaches to this class of compounds include olefination of propargyl aldehydes, [4] dehydration of propargyl alcohols, [5] and mainly metalcatalyzed cross-addition of alkynes. [6] In addition, the transition-metal-catalyzed Sonogashira coupling reaction of alkynes with vinyl halides, [7] and related cross-coupling reactions between terminal organometallic alkynes and alkenes, [8] provide prevalent methodologies for their synthesis.D espite all these remarkable progresses,there is continuous interest in the development of amore efficient and general synthesis of functionalized 1,3-enynes from readily available starting materials.…”