100869-96-3Relevant articles and documents
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.
, p. 5733 - 5742 (2019)
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 ?).
Nickel-Catalyzed 1,1-Alkylboration of Electronically Unbiased Terminal Alkenes
Li, Yangyang,Pang, Hailiang,Wu, Dong,Li, Zheqi,Wang, Wang,Wei, Hong,Fu, Ying,Yin, Guoyin
, p. 8872 - 8876 (2019)
An unprecedented nickel-catalyzed 1,1-alkylboration of electronically unbiased alkenes has been developed, providing straightforward access to secondary aliphatic boronic esters from readily available materials under very mild reaction conditions. The regioselectivity of this reaction is governed by a unique pyridyl carboxamide ligated catalyst, rather than the substrates. Moreover, this transformation shows excellent chemo- and regio-selectivity and remarkably good functional-group tolerance. We also demonstrate that under balloon pressure, ethylene can also be utilized as a substrate. Additionally, competence experiments indicate that selective bond formation is favored at the α-position of boron and preliminary mechanistic studies indicate that the key step in this three-component reaction involves a 1,2-nickel migration.
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.