68376-11-4Relevant academic research and scientific papers
ortho-C?H Arylation of Benzoic Acids with Aryl Bromides and Chlorides Catalyzed by Ruthenium
Biafora, Agostino,Krause, Thilo,Hackenberger, Dagmar,Belitz, Florian,Goo?en, Lukas J.
, p. 14752 - 14755 (2016)
A system consisting of catalytic amounts of [(p-cym)RuCl2]2/PEt3?HBF4, K2CO3as the base, and NMP as the solvent efficiently mediates the ortho-C?H arylation of benzoic acids with aryl bromides at 100 °C. Replacing the phosphine ligand with the amino acid dl-pipecolinic acid enables the analogous transformation with aryl chlorides. The key advantage of this broadly applicable transformation is the use of an inexpensive ruthenium catalyst in combination with simple carboxylates as directing groups, which can either be tracelessly removed or used as anchor points for decarboxylative ipso substitutions.
Synthesis and Utility of 2,2-Dimethyl-2 H-pyrans: Dienes for Sequential Diels-Alder/Retro-Diels-Alder Reactions
Tejedor, David,Díaz-Díaz, Abián,Diana-Rivero, Raquel,Delgado-Hernández, Samuel,García-Tellado, Fernando
supporting information, p. 7987 - 7992 (2019/01/04)
The practical use of 2,2-dimethyl-2H-pyrans as electron-rich dienes in sequential Diels-Alder/retro-Diels-Alder (DA/rDA) domino processes to generate aromatic platforms has been demonstrated. Different polysubstituted alkyl 2-naphthoates have been synthesized by the DA/rDA reaction of benzynes and 2,2-dimethyl-2H-pyrans. The use of other activated alkynes allows the access of substituted alkyl benzoate derivatives.
Selectivity-switchable construction of benzo-fused polycyclic compounds through a gold-catalyzed reaction of enyne-lactone
Luo, Kui,Zhang, Ling,Jiang, Huanfeng,Chen, Lianfen,Zhu, Shifa
supporting information, p. 1893 - 1896 (2018/02/23)
A gold-catalyzed selectivity-switchable reaction of enyne-lactone is reported. Different products, including naphthalenes and benzo-fused polycyclic compounds, can be selectively obtained from the same starting material. The choice of the gold complex is the key for the chemoselectivity of this system.
Gold-Catalyzed Ring Expansion of Enyne-Lactone: Generation and Transformation of 2-Oxoninonium
Luo, Kui,Cao, Tongxiang,Jiang, Huanfeng,Chen, Lianfen,Zhu, Shifa
supporting information, p. 5856 - 5859 (2017/11/10)
An efficient gold-catalyzed ring-expansion reaction of enyne-lactones to form 2-oxoninonium intermediates is reported. The 2-oxoninonium generated in this work could undergo further 6π electrocyclization and aromatization reaction to produce different aromatic compounds.
Photocatalytic Dehydrogenative Lactonization of 2-Arylbenzoic Acids
Ramirez, Nieves P.,Bosque, Irene,Gonzalez-Gomez, Jose C.
supporting information, p. 4550 - 4553 (2015/09/28)
A metal-free dehydrogenative lactonization of 2-arylbenzoic acids at room temperature was developed. This work illustrates the first application of visible-light photoredox catalysis in the preparation of benzo-3,4-coumarins, an important structural motif in bioactive molecules. The combination of photocatalyst [Acr+-Mes] with (NH4)2S2O8 as a terminal oxidant provides an economical and environmentally benign entry to different substituted benzocoumarins. Preliminary mechanistic studies suggest that this reaction most likely occurs through a homolytic aromatic substitution pathway.
Pd-catalyzed C-H lactonization for expedient synthesis of biaryl lactones and total synthesis of cannabinol
Li, Yan,Ding, Yan-Jun,Wang, Jian-Yong,Su, Yi-Ming,Wang, Xi-Sheng
supporting information, p. 2574 - 2577 (2013/07/11)
A practical Pd(II)/Pd(IV)-catalyzed carboxyl-directed C-H activation/C-O cyclization to construct biaryl lactones has been developed. The synthetic utility of this new reaction was demonstrated in an atom-economical and operationally convenient total synthesis of the natural product cannabinol from commercially available starting materials, with the newly developed method used for two key steps.
Construction of a tetracyclic butterfly-like scaffold: Palladium-catalyzed heck/arylation cascade
Kim, Ko Hoon,Lee, Hyun Seung,Kim, Sung Hwan,Kim, Se Hee,Kim, Jae Nyoung
supporting information; experimental part, p. 2375 - 2380 (2010/06/20)
Controlled carbopalladation: Only slight changes in the starting material (see scheme) resulted in rather different compounds in palladium-catalyzed domino reactions. A novel tetracyclic butterfly-like scaffold was constructed in a one-pot reaction via the Pd-catalyzed 5-exo-trig carbopalladation and arylation cascade in high yield.
Two methods for direct ortho-arylation of benzoic acids
Chiong, Hendrich A.,Pham, Quynh-Nhu,Daugulis, Olafs
, p. 9879 - 9884 (2008/02/13)
Two new palladium-catalyzed methods for the direct ortho-arylation of free benzoic acids have been developed. The first method employs stoichiometric silver acetate for iodide removal, aryl iodide as the coupling partner, and acetic acid solvent. This method is applicable to the arylation of electron-rich to moderately electron-poor benzoic acids and tolerates chloride and bromide substituents on both coupling partners. The second method involves the use of aryl chloride, cesium carbonate base, n-butyl-di-1-adamantylphosphine ligand, and DMF solvent and is suitable for both electron-rich and electron-poor benzoic acids. Mechanistic studies of the second method point to the heterolytic C-H bond cleavage as the rate-determining step.
