Nickel-Catalyzed Hydroalkynylation of 1,3-Dienes with Simple Alkynes
Bo-Ying Yao
,
Wei-Guo Xiao
,
Li-Jun Xiao∗
,
Qi-Lin Zhou
We thank the National Key R&D Program of China (2022YFA1503200), the National Natural Science Foundation of China (Nos. 22201140 and 22188101), the Fundamental Research Funds for the Central Universities, and the Haihe Laboratory of Sustainable Chemical Transformations for financial support.
A hydroalkynylation reaction of 1,3-dienes with simple alkynes, facilitated by an efficient nickel catalyst system with the 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (Xantphos) ligand, is presented. This reaction displays a broad substrate range for alkynes, encompassing both aryl alkynes and alkyl alkynes, thereby overcoming previous constraints in 1,3-diene hydroalkynylation. The method offers a convenient and direct means for obtaining allylic alkynes with high atom and step economy.
12 For related linear dimerizations of terminal acetylenes with 1,3-dienes, see:
Mitsudo T,
Nakagawa Y,
Watanabe K,
Hori Y,
Misawa H,
Watanabe H,
Watanabe Y.
J. Org. Chem. 1985; 50: 565
16 1,1′-[(1E)-3-Methylpent-1-en-4-yne-1,5-diyl]dibenzene (3a); Typical Procedure: In an N2-filled glove box, an oven-dried sealed tube equipped with a stirrer bar was charged with Ni(COD)2 (2.8 mg, 0.01 mmol) and Xantphos (11.6 mg, 0.02 mmol). THF (1 mL) and H2O (2.0 mmol) were injected into the tube, and the solution was stirred at 25 °C under N2 for 1 min. (E)-1-Phenyl-1,3-butadiene (1a; 39.0 mg, 0.3 mmol) and phenylacetylene (2a; 10.2 mg, 0.1 mmol) were then successively introduced into the system. The tube was sealed with a Teflon-lined screw cap and removed from the glove box, and the mixture was stirred at 60 °C for 12 h, then cooled to r.t. The resulting mixture was concentrated and the residue was purified by column chromatography (silica gel, pentane) to give a colorless oil; yield: 16.0 mg (0.069 mmol, 69%). 1H NMR (400 MHz, CDCl3): δ = 7.50–7.44 (m, 2 H), 7.41 (d, J = 7.2 Hz, 2 H), 7.37–7.28 (m, 5 H), 7.24 (d, J = 7.1 Hz, 1 H), 6.70 (dd, J = 15.7, 1.4 Hz, 1 H), 6.25 (dd, J = 15.7, 6.2 Hz, 1 H), 3.61–3.52 (m, 1 H), 1.46 (d, J = 7.0 Hz, 3 H). 13C NMR (101 MHz, CDCl3): δ = 137.1, 131.6, 131.1, 129.5, 128.5, 128.2, 127.7, 127.3, 126.3, 123.7, 91.6, 82.7, 29.6, 21.7.
