1429641-12-2Relevant articles and documents
Palladium-Catalyzed Tandem Reaction of Three Aryl Iodides Involving Triple C-H Activation
Luo, Xiai,Xu, Yankun,Xiao, Genhua,Liu, Wenjuan,Qian, Cheng,Deng, Guobo,Song, Jianxin,Liang, Yun,Yang, Chunming
, p. 2997 - 3000 (2018)
A novel palladium-catalyzed tandem reaction of N-(2-iodoaryl)acrylamides with two aryl iodides for the synthesis of spirooxindole has been achieved. The reaction underwent the process of triple C-H activation and four C-C bond formations based on the double trapping of transient spirocyclic palladacycles which are obtained through remote C-H activation.
Asymmetric δ-Lactam Synthesis with a Monomeric Streptavidin Artificial Metalloenzyme
Hassan, Isra S.,Ta, Angeline N.,Danneman, Michael W.,Semakul, Natthawat,Burns, Matthew,Basch, Corey H.,Dippon, Vanessa N.,McNaughton, Brian R.,Rovis, Tomislav
, p. 4815 - 4819 (2019)
Reliable design of artificial metalloenzymes (ArMs) to access transformations not observed in nature remains a long-standing and important challenge. We report that a monomeric streptavidin (mSav) Rh(III) ArM permits asymmetric synthesis of α,β-unsaturated-δ-lactams via a tandem C-H activation and [4+2] annulation reaction. These products are readily derivatized to enantioenriched piperidines, the most common N-heterocycle found in FDA approved pharmaceuticals. Desired δ-lactams are achieved in yields as high as 99% and enantiomeric excess of 97% under aqueous conditions at room temperature. Embedding a Rh cyclopentadienyl (Cp?) catalyst in the active site of mSav results in improved stereocontrol and a 7-fold enhancement in reactivity relative to the isolated biotinylated Rh(III) cofactor. In addition, mSav-Rh outperforms its well-established tetrameric forms, displaying 11-33 times more reactivity.
Electrochemical Difluoromethylarylation of Alkynes
Xiong, Peng,Xu, He-Huan,Song, Jinshuai,Xu, Hai-Chao
, p. 2460 - 2464 (2018)
An unprecedented radical difluoromethylarylation reaction of alkynes has been developed by discovering a new difluoromethylation reagent, CF2HSO2NHNHBoc. This air-stable and solid reagent can be prepared in one step from commercially available reagents CF2HSO2Cl and NH2NHBoc. The CF2H radical, generated through ferrocene-mediated electrochemical oxidation, participates in an unexplored alkyne addition reaction followed by a challenging 7-membered ring-forming homolytic aromatic substitution step to afford fluorinated dibenzazepines.
Disilylation of N-(2-Halophenyl)-2-phenylacrylamides with hexamethyldisilane via trapping the spirocyclic palladacycles
Xiao, Genhua,Chen, Liang,Deng, Guobo,Liu, Jianbing,Liang, Yun
, p. 1836 - 1840 (2018)
The palladium-catalyzed disilylation of the spirocyclic palladacycles with hexamethylaisilane has been realized. The key spirocyclic palladacycles are generated from N-(2-haloaryl)-2-arylacrylamide via intramolecular Heck reaction and followed remote C-H activation. A range of 3-((trimethylsilyl)methyl)-3-(2-(trimethylsilyl)phenyl)indolin-2-ones are obtained in good to excellent yields from readily available starting material under mild conditions.
Electrochemical oxidative: Z -selective C(sp2)-H chlorination of acrylamides
Coles, Simon J.,Hareram, Mishra Deepak,Harnedy, James,Morrill, Louis C.,Tizzard, Graham J.
, p. 12643 - 12646 (2021/12/07)
An electrochemical method for the oxidative Z-selective C(sp2)-H chlorination of acrylamides has been developed. This catalyst and organic oxidant free method is applicable across various substituted tertiary acrylamides, and provides access to a broad range of synthetically useful Z-β-chloroacrylamides in good yields (22 examples, 73% average yield). The orthogonal derivatization of the products was demonstrated through chemoselective transformations and the electrochemical process was performed on gram scale in flow.
Rhodium(III)-Catalyzed Aerobic Oxidative C-H Olefination of Unsaturated Acrylamides with Unactivated Olefins
Logeswaran, Ravichandran,Jeganmohan, Masilamani
supporting information, p. 767 - 771 (2021/02/06)
A rhodium(III)-catalyzed aerobic oxidative cross-coupling of acrylamides with unactivated alkenes via vinylic C-H activation has been developed. The present cross-coupling reaction was examined with a variety of differently functionalized acrylamides and unactivated olefins. In these reactions, highly valuable amide-functionalized butadienes were prepared in good to excellent yields. This protocol was also compatible with Weinreb amides. A possible reaction mechanism involving the chelation-assisted vinylic C-H activation via a carboxylate-assisted deprotonation pathway is proposed.
Palladium-catalyzed intermolecular C-H silylation initiated by aminopalladation
Ji, Xiaoming,Wei, Feng,Wan, Bin,Cheng, Cang,Zhang, Yanghui
, p. 7801 - 7804 (2020/07/27)
A Pd(ii)-catalyzed intermolecular C-H silylation reaction initiated by aminopalladation has been developed. The C-H bonds were activated by an alkyl Pd(ii) species generated through aminopalladation and then disilylated with hexamethyldisilane to form disilylated indolines as the final products. The reaction provides a new method for the introduction of silyl groups into complex organic molecules.
Palladium-Catalyzed C?H Silylation through Palladacycles Generated from Aryl Halides
Lu, Ailan,Ji, Xiaoming,Zhou, Bo,Wu, Zhuo,Zhang, Yanghui
, p. 3233 - 3237 (2018/02/23)
A highly efficient palladium-catalyzed disilylation reaction of aryl halides through C?H activation has been developed for the first time. The reaction has broad substrate scope. A variety of aryl halides can be disilylated by three types of C?H activation, including C(sp2)?H, C(sp3)?H, and remote C?H activation. In particular, the reactions are also unusually efficient. The yields are essentially quantitative in many cases, even in the presence of less than 1 mol % catalyst and 1 equivalent of the silylating reagent under relatively mild conditions. The disilylated biphenyls can be converted into disiloxane-bridged biphenyls.
Water as a Hydride Source in Palladium-Catalyzed Enantioselective Reductive Heck Reactions
Kong, Wangqing,Wang, Qian,Zhu, Jieping
, p. 3987 - 3991 (2017/03/27)
Pd-catalyzed intramolecular asymmetric carbopalladation of N-aryl acrylamides followed by reduction of C(sp3)-Pd intermediate using diboron–water as a hydride source afforded enantioenriched 3,3-disubstituted oxindoles in high yields and enantioselectivities. When heavy water was used as a deuterium donor in combination with bis(catecholato)diboron (Cat2B2), deuterium was incorporated into the products with high synthetic efficiency. The ligand determined both the enantioselectivity of the reaction and the reaction pathways, thereby affording either hydroarylation (reductive Heck) or carboborylation products.
An approach to spirooxindoles: Via palladium-catalyzed remote C-H activation and dual alkylation with CH2Br2
Shao, Changdong,Wu, Zhuo,Ji, Xiaoming,Zhou, Bo,Zhang, Yanghui
, p. 10429 - 10432 (2017/09/25)
A facile and efficient approach for the synthesis of spirooxindoles has been developed via the coupling of spirocyclic C,C-palladacycles with CH2Br2. The key spirocyclic palladacycles are generated catalytically via remote C-H activation. A range of spirooxindoles can be synthesized in good to excellent yields from readily available starting material.