Study Of Rhodium Catalyzed C-C Bond Activation Reactions

Transition-metal-catalyzed carbon-carbon bond activation can realize rapid construction of complex organic molecules,and it is a hotspot in the field of organic synthesis.Since carbon-carbon bonds have high thermodynamic and kinetic stability,it is not easy to activate carbon-carbon bonds.Usually,the necessary activation strategy need to be taken to achieve the transition-metal-catalyzed carbon-carbon bond activation.For the strained ring molecules,the carbon-carbon bond activation is commonly achieved by releasing ring tension.For unstrained ring molecules,carbon-carbon bond activation is achieved primarily by ?-alkyl elimination,functional group chelation.Based on the above synthetic strategies,several substrates with different structures were designed and selected to apply in transition-metal-catalyzed carbon-carbon bond activation reactions,a series of new chemical reactions were achieved via the catalysis of rhodium catalyst,and a series of substituted compounds were synthesized.1.Rhodium-Catalyzed Coupling Reactions of Aromatic Primary Alcohols and Arylboronic Acids via C-C Bond Activation.(Benzo[h]quinolin-10-yl)methanol was synthesized,and rhodium-catalyzed coupling reaction of(benzo[h]quinolin-10-yl)methanols with aryl boronic acids via C-C bond activation was achieved to prepare unsymmetrical biaryls.The desired unsymmetrical biaryl products were obtained in good to excellent yields under the optimized reaction conditions.Various functionalized primary alcohols and arylboronic acids are compatible with the reaction under the optimized conditions.The significance of this new coupling reaction is to achieve the transition metal catalyzed C-C bond activation reaction of primary alcohol with the aid of chelating group.2.Rhodium-Catalyzed Decarboxylation Annulation Reactions of Mandelic Acids and Alkynes.According to the strategy of the C-C bond activation with the assistance of detachable directing groups,commercially available mandelic acid as the reaction substrate was used.Rhodium-catalyzed decarboxylation annulation reactions between mandelic acids and alkyne derivatives to prepare indenone products are achieved.Mandelic acids and alkynes substituted by various functional groups are compatible with the reaction under the optimized reaction conditions.The desired indenone products were obtained in medium to good yields under the optimized reaction conditions.3.Rhodium-Catalyzed Decarbonylative Cycloadditions of 1H-indene-1,2,3-triones and Alkynes via C-C Bond Activation.1H-indene-1,2,3-trione without directing group was used as the reaction substrate,a preparation method for indenone and quinone derivatives via a rhodium-mediated decarbonylative cycloaddition of 1H-indene-1,2,3-triones and alkynes has been achieved.A [Rh(COD)Cl]2 with a rac-BINAP ligand was the most efficient catalytic system for this decarbonylative cycloaddition transformation.The [5+2-2] or [5+2-1] transformation processes can be enhanced respectively by adding CuCl2 or Cr(CO)6 as an additive.This reaction is suitable for a broad range of alkynes and 1H-indene-1,2,3-triones and a variety of fused indenone or quinone derivatives were obtained in medium to high yields.4.Rhodium-Catalyzed Decarbonylative Coupling Reaction of Aryl Aldehyde with Iodobenzenes via C-C Bond Activation.Benzo[h]quinoline-10-carbaldehyde was synthesized,and rhodium-catalyzed decarbonylative coupling reaction between benzo[h]quinoline-10-carbaldehyde and iodobenzenes to prepare unsymmetrical biaryls was achieved.Various functionalized iodobenzenes are compatible with the reaction under the optimized conditions.The desired unsymmetrical biaryl products were obtained in good to excellent yields under the optimized reaction conditions.