Study Of Chelating-Assisted Ruthenium Catalyzed Alkyl Exchange And Nickel Catalyzed Synthesis Of Tertiol Reactions

Transition-metal catalyzed carbon-carbon bond activation reaction is a new method to construct complex organic compounds.Because of the advantages in atomic economy and environmental benign,this new synthesis method has a good application prospect in the synthesis of complex organic compounds such as natural compounds,and drug intermediates.However,due to the high thermodynamic and kinetic stability,the carbon-carbon bond activation is usually difficult to realize.Herein,we summarize the latest development of transitional-metal catalyzed C-C bond activation reactions.Based on the directing group mediated carbon-carbon bond activation strategy,we design and synthesize the 1-(quinoline-8-group)propyl-1-one compound containing a N-directing group.Under the reaction condition of DPPP as ligand and triethylamine as base,we achieve the alkyl group exchange of ketone with styrene in the presence of rhodium catalyst.A series of substituted3-phenyl-1-(quinoline-8-yl)propyl-1-ketone compounds were obtained in medium to good yields.Tertiary alcohols are important compounds that are widely found in natural products,drugs,and dye molecules.Traditionally,these compounds were synthesized by the addition reaction of a Grignard reagent,or a organic zinc reagent to a ketone.However,these traditional methods suffer many disadvantages such as harsh reaction conditions,side reactions,and poor functional group adaptability.In this paper,a nickel-catalyzed addition reaction of arylboronic acid to1-(quinolin-8-yl)ethan-1-one to produce tertiary alcohols or secondary alcohols was developed.Arylboronic acids were used as nucleophiles instead of the Grignard reagents or organic zinc reagents,which results better functional group adaptability.A series of substituted 1-aryl-1-(quinoline-8-group)ethyl-1-alcohol compounds were obtained in good to excellent yields.The addition amount of Na I significantly affects the reaction efficiency,and it proves that the coordination of iodide to the metal center is important for promoting the catalytic cycles.In the light of relevant literatures and current experimental data,a possible reaction mechanism was proposed.Finally,it is found that the directing group is essential for the smooth addition of arylboronic acids to the ketones.