Bai D,
*,
Zhong K,
Chang L,
Qiao Y,
Wu F,
Xu G,
Chang J.
*
Henan Normal University, Xinxiang and Shanghai Institute of Organic Chemistry, P. R. of China
Nickel-Catalyzed Regiodivergent Hydrosilylation of α-(Fluoroalkyl)styrenes without Defluorination.
Nat. Commun. 2024;
15: 6360
DOI:
10.1038/s41467-024-50743-w
Key words
nickel catalysis - hydrosilylation - regiodivergent synthesis
Significance
A regiodivergent hydrosilylation reaction of α-(fluoroalkyl)styrenes is reported to occur under mild conditions and with commercially available ligands providing both α- and β-trifluoromethyl-substituted scaffolds. With the bidentate ligand BINAP, the reaction proceeds via a Markovnikov pathway, selectively forming products with a quaternary center, without any by-products from β-F elimination. In contrast, use of the monodentate PPh3 ligand promotes the traditional anti-Markovnikov addition pathway.
Comment
Experimental data support a polar mechanism involving the addition of a NiH species. Control experiments demonstrate that the trifluoromethyl group is essential for reactivity; in its absence, only anti-Markovnikov products are formed. DFT analysis confirms that a [1,2]-migratory insertion followed by reductive elimination (Path A) is favored in the presence of BINAP, which the authors attribute to the σ-withdrawing effect of the trifluoromethyl group.
