20485-57-8Relevant articles and documents
Palladium-catalyzed expedient Heck annulations in 1-bromo-1,5-dien-3-ols: Exceptional formation of fused bicycles
Ray, Jayanta K.,Singha, Raju,Ray, Devalina,Ray, Paramita,Rao, Davuluri Yogeswara,Anoop, Anakuthil
, p. 931 - 935 (2019)
An unprecedented Pd-catalyzed intramolecular Heck cyclization has been investigated on halogenated diene scaffolds undergoing various mode of cyclization and termination leading to the formation of structurally differing fused cyclopenta(e)none and aromatic analogue. The discrimination in the fate of palladium intermediates formed in situ undergoing Heck cyclization preferentially arises out of the difference in reaction temperature as well as substrate architecture. Sequential Heck reaction of 1-Bromo-5-methyl-1-aryl-hexa-1,5-dien-3-ol derivatives followed by oxidation or termination via sp2 C–]H activation in aromatic ring led to the formation of fused cyclopentanes. However, the similar reaction at elevated temperature showed predominance towards the formation of aromatic analogues via one pot cyclization and dehydroxylation. The mechanism for the formation of cyclopentanone fused with cyclopropane ring system is supported by density functional theory based calculations.
Benzannulation via ruthenium-catalyzed diol-diene [4+2] cycloaddition: One- and two-directional syntheses of fluoranthenes and acenes
Geary, Laina M.,Chen, Te-Yu,Montgomery, T. Patrick,Krische, Michael J.
, p. 5920 - 5922 (2014/05/20)
A new benzannulation protocol is described and applied to the synthesis of polycyclic aromatic hydrocarbons. Ruthenium(0)-catalyzed diol-diene [4+2] cycloaddition delivers cyclohex-1-ene-4,5-diols, which are subject to aromatization upon dehydration or Nicholas diol deoxydehydration. Employing diol and tetraol reactants, benzannulation can be conducted efficiently in one- and two-directional modes, respectively, as illustrated in the construction of substituted fluoranthenes and acenes.
