68899-41-2Relevant 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 ?).
Synthesis of alkylidene pyrrolo[3,4-b]pyridin-7-one derivatives via Rh III-catalyzed cascade oxidative alkenylation/annulation of picolinamides
Martínez, ángel Manu,Rodríguez, Nuria,Gómez Arrayás, Ramón,Carretero, Juan C.
supporting information, p. 6105 - 6107 (2014/06/09)
A practical RhIII-catalyzed cascade olefination/annulation of picolinamides leading to pyrrolo[3,4-b]pyridines has been developed. The reaction shows wide scope, complete regiocontrol and excellent stereoselectivity. This journal is the Partner Organisations 2014.
Facile preparation of amides from carboxylic acids and amines with ion-supported Ph3P
Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
, p. 3971 - 3977 (2013/06/27)
Ion-supported Ph3P, 4-(diphenylphosphino)benzyltrimethylammonium bromide (IS-Ph3P), could be used for the facile amidation of a wide range of carboxylic acids with amines in the presence of bromotrichloromethane to provide the corresponding amides in good yields. In the present reaction, the desired amides were obtained in good yields with high purity by simple extraction of the reaction mixture with diethyl ether or chloroform and subsequent removal of the solvent from the extract. Moreover, ion-supported Ph3PO (IS-Ph3PO), which was a co-product derived from IS-Ph3P in the present reductive condensation, was recovered in high yield and could be reduced to IS-Ph3P for reuse in the same amidation of carboxylic acid.
A STUDY OF PHOTOCYCLIZATION OF O-ALKYL N-(3-CHLORO-2-BENZOTHIENOCARBONYL)MONOTHIOCARBAMATES
Kutschy, Peter,Imrich, Jan,Bernat, Juraj,Kristian, Pavol,Fedorikova, Iveta
, p. 2002 - 2012 (2007/10/02)
The O-alkyl N-(3-chloro-2-benzothienocarbonyl)monothiocarbamates prepared by the reaction of 2-isothiocyanatocarbonyl-3-chlorobenzothiophene with methanol, ethanol, 1-propanol, and 2-propanol are cyclized on irradiation with light of the wavelength
