795283-79-3Relevant academic research and scientific papers
Rhodium-Catalyzed Copper-Assisted Intermolecular Domino C?H Annulation of 1,3-Diynes with Picolinamides: Access to Pentacyclic π-Extended Systems
Martínez, ángel Manu,Alonso, Inés,Rodríguez, Nuria,Gómez Arrayás, Ramón,Carretero, Juan C.
supporting information, p. 5733 - 5742 (2019/04/03)
A new mode of reactivity of 1,3-diynes in rhodium-catalyzed oxidative annulation reactions has enabled the rapid assembly of extended π systems from readily available picolinamide derivatives. The process involves a double C?H bond activation and the iterative annulation of two 1,3-diyne units, with each alkyne moiety engaged in an orchestrated insertion sequence with high regiocontrol, leading to the formation of five new C?C bonds and the construction of four fused rings in a single operation. Either isoquinoline-1-carboxamides or fused polycyclic systems can be accessed by a switch in the regioselectivity of the second diyne insertion depending on the reaction conditions. DFT theoretical calculations have elucidated that the cooperative participation of both rhodium and copper in substrate activation, favored in the presence of excess of the copper(II) salt, is key to such a reversal of regioselectivity and subsequent multiple cyclization leading to fused polycyclic products. The role of copper was found to be essential in assisting both multiple insertion and rhodium-walking sequences, with the implication of intermediates with a Rh?Cu bond (2.60 ?).
Pd(II)-Catalyzed Direct Sulfonylation of Benzylamines Using Sodium Sulfinates
Karmakar, Ujjwal,Samanta, Rajarshi
, p. 2850 - 2861 (2019/03/29)
A Pd(II)-catalyzed direct sulfonylation of benzylamines with sodium sulfinates using a removable bidentate directing group is illustrated. The transformation is highly regioselective and tolerates wide functional groups. The mechanistic study reveals that radical species are involved in this reaction. This method delivers a direct synthetic strategy to obtain highly functionalized sulfonylated benzylamines.
Tetramethyl Orthosilicate (TMOS) as a Reagent for Direct Amidation of Carboxylic Acids
Braddock, D. Christopher,Lickiss, Paul D.,Rowley, Ben C.,Pugh, David,Purnomo, Teresa,Santhakumar, Gajan,Fussell, Steven J.
supporting information, p. 950 - 953 (2018/02/23)
Tetramethyl orthosilicate (TMOS) is shown to be an effective reagent for direct amidation of aliphatic and aromatic carboxylic acids with amines and anilines. The amide products are obtained in good to quantitative yields in pure form directly after workup without the need for any further purification. A silyl ester as the putative activated intermediate is observed by NMR methods. Amidations on a 1 mol scale are demonstrated with a favorable process mass intensity.
Cobalt-Catalyzed ortho-C?H Functionalization/Alkyne Annulation of Benzylamine Derivatives: Access to Dihydroisoquinolines
Martínez, ángel Manu,Rodríguez, Nuria,Gómez-Arrayás, Ramón,Carretero, Juan C.
supporting information, p. 11669 - 11676 (2017/08/30)
A practical picolinamide-directed C?H functionalization/alkyne annulation of benzylamine derivatives enabling access to the previously elusive 1,4-dihydroisoquinoline skeleton was developed using molecular O2 as the sole oxidant and Co(OAc)2 as precatalyst. The method is compatible with both internal and terminal alkynes and shows high versatility and functional-group tolerance. Furthermore, full preservation of enantiopurity is observed when using non-racemic α-substituted benzylamine derivatives. Kinetic analysis of the reagents and catalyst, labeling experiments, and the isolation and identification of catalytically competent Co-complexes revealed important insights about the mechanism.
Cobalt-Catalyzed Selective Synthesis of Isoquinolines Using Picolinamide as a Traceless Directing Group
Kuai, Changsheng,Wang, Lianhui,Li, Bobin,Yang, Zhenhui,Cui, Xiuling
supporting information, p. 2102 - 2105 (2017/04/27)
Picolinamide has first been employed as a traceless directing group for the cobalt-catalyzed oxidative annulation of benzylamides with alkynes to synthesize isoquinolines through C-H/N-H bonds activation. Oxygen is used as a terminal oxidant. This protocol exhibits good functional group tolerance and excellent regioselectivity. Both terminal and internal alkynes can be efficiently applied to this catalytic system as substrates.
Synthesis of imides by palladium-catalyzed C-H functionalization of aldehydes with secondary amides
Bian, Yong-Jun,Chen, Chao-Yue,Huang, Zhi-Zhen
supporting information, p. 1129 - 1133 (2013/02/23)
An efficient palladium-catalyzed C-H functionalization of aldehydes with various N-substituted N-heteroarene-2-carboxamides has been developed for the synthesis of secondary imides. The reaction tolerates various functionalities, such as methoxy, fluoro, chloro, and bromo groups. A tentative radical mechanism for a PdII/PdIV catalytic cycle is proposed. Copyright
Palladium-catalyzed aryl C-H bonds activation/acetoxylation utilizing a bidentate system
Gou, Fa-Rong,Wang, Xiang-Chuan,Huo, Peng-Fei,Bi, Hai-Peng,Guan, Zheng-Hui,Liang, Yong-Min
supporting information; experimental part, p. 5726 - 5729 (2010/03/01)
[Chemical Equation Presented] A palladium-catalyzed aryl C-H bonds activation/acetoxylation reaction utilizing a bidentate system has been explored. This transformation has been applied to a wide array of pyridine and 8-aminoquinoline derivatives and it exhibits excellent functional group tolerance.
