4173-44-8Relevant articles and documents
C3-Thioester/-Ester Substituted Linear Dienones: A Pluripotent Molecular Platform for Diversification via Cascade Pericyclic Reactions
Bankura, Abhijit,Naskar, Sandip,Roy Chowdhury, Sabyasachi,Maity, Rajib,Mishra, Sabyashachi,Das, Indrajit
, p. 3604 - 3612 (2020)
Substituted oxabicyclo derivatives bearing two quaternary carbon centers and five contiguous stereocenters have been synthesized from C3-thioester/-ester substituted dienones, a simple and linear pluripotent molecular platform. The conversion proceeds from neat reactants, possibly via a thermally-driven pericyclic cascade manifold involving sequential (E)-s-trans to (E)-s-cis isomerization, oxa-6π-electrocyclization, and intermolecular, regioselective [4π+2π] cycloaddition. The proposed mechanism has been substantiated by intermediate trapping experiments and DFT studies. Such dienones have also been exploited to effect stereoselective cross Diels-Alder cycloadditions with olefins and sequential Diels-Alder/retro-Diels-Alder reactions with activated alkynes. The reaction is greatly influenced by the substituent effect exerted by the C3-thioester/-ester group. (Figure presented.).
Direct Catalytic Asymmetric Synthesis of Disubstituted 4-Oxocyclohexanecarbaldehydes from Acetone and Cinnamaldehyde Derivatives
Maurya, Vidyasagar,Kutwal, Mahesh S.,Appayee, Chandrakumar
, p. 1566 - 1571 (2021)
A first catalytic asymmetric reaction of acetone with cinnamaldehyde for the synthesis of disubstituted 4-oxocyclohexanecarbaldehyde is developed. A variety of substituted cinnamaldehydes are successfully tested under the optimized reaction conditions. Both the enantiomers of the same diastereomeric products are achieved in good yield and diastereoselectivity with an excellent enantioselectivity by changing the enantiomer of one of the two chiral catalysts. The practicality of this methodology is demonstrated by the gram-scale synthesis.
Hydroperoxidations of Alkenes using Cobalt Picolinate Catalysts
Peralta-Neel, Zulema,Woerpel
supporting information, p. 5002 - 5006 (2021/06/30)
Hydroperoxides were synthesized in one step from various alkenes using Co(pic)2as the catalyst with molecular oxygen and tetramethyldisiloxane (TMDSO). The hydration product could be obtained using a modified catalyst, Co(3-mepic)2, with molecular oxygen and phenylsilane. Formation of hydroperoxides occurred through a rapid Co-O bond metathesis of a peroxycobalt compound with isopropanol.
Palladium-Catalyzed Aminomethylation of Nitrodienes and Dienones via Double C—N Bond Activation
Yu, Bangkui,Gao, Bao,Zhang, Xuexia,Zhang, Haocheng,Huang, Hanmin
supporting information, p. 566 - 570 (2021/02/01)
A new strategy for the generation of the active Pd-alkyl species from aminal via C—N bond activation has been established, in which the formation of zwitterionic intermediate through aza-Michael addition of aminal to nitrodienes or dienones is identified as a key step for the activation of the C—N bond. The efficient strategy has enabled a new palladium-catalyzed α-aminomethylation of nitrodienes and dienones via double C—N bond activation. The scope and versatility of the reaction were demonstrated and a broad range of substrates bearing electron-donating and -withdrawing groups on the aromatic rings were all compatible with this reaction to furnish the desired α-aminomethylated products in moderate to good yields with excellent regioselectivities and E/Z selectivities.
