Categories: C-C Bond Formation > Arenes, Alkynes >

Alkynylation

Name Reactions

Versatile Cross Coupling Methods:

Hiyama Coupling (R-X + R'-SiR''₃)

Hiyama-Denmark Coupling (R-X + R-SiMe₂OH)

Kumada Coupling (R-X + R'-MgX)

Negishi Coupling (R-X + R'-ZnX)

Stille Coupling (R-X + R'-SnR''₃)

Suzuki Coupling (R-X + R'-BY₃)

Recent Literature

An efficient ligand-, copper-, and amine-free palladium-catalyzed Sonogashira reaction of aryl iodides and bromides with terminal alkynes at room temperature has been developed. The key reagent is tetrabutylammonium acetate as the base. This method tolerates a broad range of functional groups.
S. Urgaonkar, J. G. Verkade, J. Org. Chem., 2004, 69, 5752-5755.

A highly efficient and practical protocol for the coupling of terminal alkynes with aryl iodides is catalyzed by the inexpensive and environmentally benign combination of Fe/Cu. The versatility, generality, low cost, and environmental friendliness, in combination with exceptionally high reaction rates, render this method particularly attractive for industrial applications.
H. Huang, H. Jiang, K. Chen, H. Liu, J. Org. Chem., 2008, 73, 9061-9064.

An inexpensive catalytic system using a readily available copper/ligand combination for the Sonogashira-type cross-coupling of aryl iodides and phenyl- and hexyl-acetylene affords disubstituted alkynes in good yields.
F. Monnier, F. Turtaut, L. Duroure, M. Taillefer, Org. Lett., 2008, 10, 3203-3206.

General protocols for the palladium-catalyzed coupling of aryl chlorides and alkynes and aryl tosylates and alkynes were developed. Addition of a copper cocatalyst can inhibit product formation. In the case of highly active catalysts, screening for new catalyst systems need to be carried out both in the presence and absence of copper.
D. Gelman, S. L. Buchwald, Angew. Chem. Int. Ed., 2003, 42, 5993-5996.

The palladium-catalyzed cross-coupling reaction of potassium alkynyltrifluoroborates with aryl halides or triflates proceeds readily with moderate to excellent yields. The potassium alkynyltrifluoroborates are air- and moisture-stable crystalline solids that can be stored indefinitely, which will provide an advantage in applications to combinatorial chemistry.
G. A. Molander, B. W. Katona, F. Machrouhi, J. Org. Chem., 2002, 67, 8416-8423.

A triethylamine-catalyzed metalation of terminal alkynes with trimethylaluminum (a readily available, inexpensive, and nontoxic metalating agent) gives alkynyldimethylaluminum reagents. These compounds react efficiently with various aromatic and heterocyclic halides in the presence of a palladium catalyst offering a simple entry to numerous internal alkynes.
B. Wang, M. Bonin, L. Micouin, Org. Lett., 2004, 6, 3481-3484.

Cross-Coupling of Alkynylsilanols with Aryl Halides Promoted by Potassium Trimethylsilanolate
S. E. Denmark, S. A. Tymonko, J. Org. Chem., 2003, 68, 9151-9154.

Employing propiolic acid as a difunctional alkyne, and using the consecutive reactions of a Sonogashira coupling and a decarboxylative coupling, unsymmetrically substituted diaryl alkynes were obtained in good yield.
J. Moon, M. Jeong, H. Nam, J. Ju, J. H. Moon, H. M. Jung, S. Lee, Org. Lett., 2008, 10, 945-948.

Various substituted phenols are ethynylated at the ortho position with silylated chloroethyne in the presence of a catalytic amount of GaCl₃ and lithium phenoxide. The lithium salt is essential for the catalysis, and addition of 2,6-di(tert-butyl)-4-methylpyridine inhibits desilylation and hydration of the products. The mechanism is discussed.
K. Kobayahi, M. Arisawa, M. Yamaguchi, J. Am. Chem. Soc., 2002, 124, 8528-8529.

A carbenoid Fritsch-Buttenberg-Wiechell (FBW) rearrangement of a substituted dibromoolefinic precursor is used to generate a lithium acetylide, and subsequent trapping with carbon-based electrophiles provides a wide range of di- and triynes. The lithium acetylide formed from the FBW reaction can also undergo transmetalation to provide zinc, copper, tin, or platinum acetylides.
T. Luu, Y. Morisaki, N. Cunningham, R. R. Tykwinski, J. Org. Chem., 2007, 72, 9622-9629.