1616337-39-3Relevant academic research and scientific papers
Bifunctional Ligand-Assisted Catalytic Ketone α-Alkenylation with Internal Alkynes: Controlled Synthesis of Enones and Mechanistic Studies
Mo, Fanyang,Lim, Hee Nam,Dong, Guangbin
supporting information, p. 15518 - 15527 (2015/12/26)
Here, we describe a detailed study of the rhodium(I)-catalyzed, bifunctional ligand-assisted ketone α-C-H alkenylation using internal alkynes. Through controlling the reaction conditions, conjugated enamines, α,β- or β,γ-unsaturated ketones, can be selectively accessed. Both aromatic and aliphatic alkynes can be employed as coupling partners. The reaction conditions also tolerate a broad range of functional groups, including carboxylic esters, malonates, secondary amides, thioethers, and free alcohols. In addition, excellent E-selectivity was observed for the tetra-substituted alkene when forming the α,β-unsaturated ketone products. The mechanism of this transformation was explored through control experiments, kinetic monitoring, synthesizing the rhodium-hydride intermediates and their reactions with alkynes, deuterium-labeling experiments, and identification of the resting states of the catalyst.
Regioselective ketone α-alkylation with simple olefins via dual activation
Mo, Fanyang,Dong, Guangbin
, p. 68 - 72 (2014/07/21)
Alkylation of carbonyl compounds is a commonly used carbon-carbon bond-forming reaction. However, the conventional enolate alkylation approach remains problematic due to lack of regioselectivity, risk of overalkylation, and the need for strongly basic conditions and expensive alkyl halide reagents. Here, we describe development of a ketone-alkylation strategy using simple olefins as the alkylating agents. This strategy employs a bifunctional catalyst comprising a secondary amine and a low-valent rhodium complex capable of activating ketones and olefins simultaneously. Both cyclic and acyclic ketones can be mono-a-alkylated with simple terminal olefins, such as ethylene, propylene, 1-hexene, and styrene, selectively at the less hindered site; a large number of functional groups are tolerated.The pH/redox neutral and byproduct-free nature of this dual-activation approach shows promise for large-scale syntheses.
