34450-48-1Relevant academic research and scientific papers
Photoinduced transition-metal- And external-photosensitizer-free intramolecular aryl rearrangementviaC(Ar)-O bond cleavage
Dou, Qian,Li, Chao-Jun,Zeng, Huiying
, p. 5740 - 5744 (2020/06/26)
The use of photochemical reactions that do not require expensive photocatalysts or transition metals is an environmentally friendly strategy for accomplishing a variety of structural transformations. Herein, we report a protocol for photoinduced transition-metal- and external-photocatalyst-free intramolecular heteroaryl/aryl rearrangement reactions of 2-heteroaryl/aryloxybenzaldehydes. The protocol was compatible with a variety of functionalities, including methyl, methoxy, cyano, ester, trifluoromethyl, halogen, and heteroaromatic rings. Control experiments suggested that the reaction proceededviaa photoinduced intramolecular heteroaryl/aryl rearrangement process involving photoexcitation of the aldehyde carbonyl group, radical addition, C-C bond formation and C(Ar)-O bond cleavage.
C?H Oxygenation Reactions Enabled by Dual Catalysis with Electrogenerated Hypervalent Iodine Species and Ruthenium Complexes
Massignan, Leonardo,Tan, Xuefeng,Meyer, Tjark H.,Kuniyil, Rositha,Messinis, Antonis M.,Ackermann, Lutz
supporting information, p. 3184 - 3189 (2020/01/24)
The catalytic generation of hypervalent iodine(III) reagents by anodic electrooxidation was orchestrated towards an unprecedented electrocatalytic C?H oxygenation of weakly coordinating aromatic amides and ketones. Thus, catalytic quantities of iodoarenes in concert with catalytic amounts of ruthenium(II) complexes set the stage for versatile C?H activations with ample scope and high functional group tolerance. Detailed mechanistic studies by experiment and computation substantiate the role of the iodoarene as the electrochemically relevant species towards C?H oxygenations with electricity as a sustainable oxidant and molecular hydrogen as the sole by-product. para-Selective C?H oxygenations likewise proved viable in the absence of directing groups.
Ruthenium-Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H2
Hu, Le' an,Zhang, Yao,Zhang, Qing-Wen,Yin, Qin,Zhang, Xumu
supporting information, p. 5321 - 5325 (2020/02/28)
A Ru-catalyzed direct asymmetric reductive amination of ortho-OH-substituted diaryl and sterically hindered ketones with ammonium salts is reported. This method represents a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97 % yield, 93–>99 % ee). Elaborations of the chiral amine products into bioactive compounds and a chiral ligand were demonstrated through manipulation of the removable and convertible -OH group.
Deoxygenative Arylation of Carboxylic Acids by Aryl Migration
Ruzi, Rehanguli,Ma, Junyang,Yuan, Xiang-Ai,Wang, Wenliang,Wang, Shanshan,Zhang, Muliang,Dai, Jie,Xie, Jin,Zhu, Chengjian
supporting information, p. 12724 - 12729 (2019/11/05)
An unprecedented deoxygenative arylation of aromatic carboxylic acids has been achieved, allowing the construction of an enhanced library of unsymmetrical diaryl ketones. The synergistic photoredox catalysis and phosphoranyl radical chemistry allows for precise cleavage of a stronger C?O bond and formation of a weaker C?C bond by 1,5-aryl migration under mild reaction conditions. This new protocol is independent of substrate redox-potential, electronic, and substituent effects. It affords a general and promising access to 60 examples of synthetically versatile o-amino and o-hydroxy diaryl ketones under redox-neutral conditions. Furthermore, it also brings one concise route to the total synthesis of quinolone alkaloid, (±)-yaequinolone A2, and a viridicatin derivative in satisfying yields.
Rhodium-Catalyzed Directing-Group-Assisted Aldehydic C–H Arylations with Aryl Halides
Rao, Maddali L. N.,Ramakrishna, Boddu S.
, p. 5080 - 5093 (2017/09/20)
A rhodium-catalyzed general protocol for the directing-group-assisted arylation of aromatic aldehydic C–H bonds was developed. This method involves either hydroxy- or amino-group-directed aldehyde C–H arylation with various aryl halides. A broad synthetic scope for the preparation of 2-hydroxybenzophenones was established with electronically variant salicylaldehydes and aryl halides with chemo- and regioselective possibilities. The developed protocol was also applied in the synthesis of medicinally important 3-salicyloylpyridines in high yields.
Iridium- and rhodium-catalyzed C-H activation and formyl arylation of benzaldehydes under chelation-assistance
Yang, Xifa,Wang, He,Zhou, Xukai,Li, Xingwei
supporting information, p. 5233 - 5237 (2016/07/06)
Mild and efficient synthesis of benzophenones via Ir(iii)- and Rh(iii)-catalyzed, directing group-assisted formyl C-H arylation of benzaldehydes has been achieved using diaryliodonium salts, in which Rh(iii) and Ir(iii) catalysts exhibited a complementary
Synthesis of ortho-hydroxybenzophenones catalyzed by magnetically retrievable Fe3O4 nanoparticles under ligand-free conditions
Ramani, Thekkathu,Umadevi, Paspulati,Prasanth, K. Leon,Sreedhar, Bojja
supporting information, p. 6021 - 6026 (2013/09/24)
ortho-Benzoylation of phenols with aryl aldehydes to afford the substituted 2-hydroxybenzophenones can be catalyzed efficiently by Fe3O 4 nanoparticles under ligand-free conditions. This method is useful for the preparation of xanthones in good yields. The catalyst can be magnetically removed and recycled easily over four cycles without a significant decrease in activity. The applicability of magnetically retrievable Fe 3O4 nanoparticles in the oxidative coupling of aryl aldehydes with phenols under ligand free conditions is demonstrated.
Direct C-H bond arylation of 2-hydroxybenzaldehydes with arylboronic acids via ligand-free palladium catalysis
Weng, Fei,Wang, Chengming,Xu, Bin
supporting information; experimental part, p. 2593 - 2596 (2010/07/04)
A mild and efficient ligand-free palladium-catalyzed direct C-H bond arylation reaction was developed to afford 2-hydroxybenzophenones in good to excellent yields from easily available 2-hydroxybenzaldehydes and arylboronic acids. The given reaction provided one of the easiest pathways for accessing 2-hydroxybenzophenones, and a variety of functional groups could be tolerated in this process.
Reactions of 2-hydroxybenzophenones with Corey-Chaykovsky reagent
Chittimalla, Santhosh Kumar,Chang, Tsung-Che,Liu, Ting-Chun,Hsieh, Hsing-Pang,Liao, Chun-Chen
, p. 2586 - 2595 (2008/09/19)
A variety of 2-hydroxybenzophenones on reaction with Corey-Chaykovsky reagent underwent unprecedented rearrangements leading to 3-substituted benzofurans 8 and one-carbon homologated compounds 9 and 12. Compounds 9 could further be quantitatively transfor
