23637-46-9Relevant academic research and scientific papers
Catalyst-controlled regioselectivity in the synthesis of branched conjugated dienes via aerobic oxidative heck reactions
Zheng, Changwu,Wang, Dian,Stahl, Shannon S.
supporting information, p. 16496 - 16499,4 (2020/09/15)
Pd-catalyzed aerobic oxidative coupling of vinylboronic acids and electronically unbiased alkyl olefins provides regioselective access to 1,3-disubstituted conjugated dienes. Catalyst-controlled regioselectivity is achieved by using 2,9-dimethylphenanthroline as a ligand. The observed regioselectivity is opposite to that observed from a traditional (nonoxidative) Heck reaction between a vinyl bromide and an alkene. DFT computational studies reveal that steric effects of the 2,9-dimethylphenanthroline ligand promote C-C bond formation at the internal position of the alkene.
A New Version of the Peterson Olefination Using Bis(trimethylsilyl)methyl Derivatives and Fluoride Ion as Catalyst
Palomo, Claudio,Aizpurua, Jesus M.,Garcia, Jesus M.,Ganboa, Inaki,Cossio, F. P.,et al.
, p. 2498 - 2503 (2007/10/02)
Reaction between a variety of bis(trimethylsilyl)methyl derivatives and carbonyl compounds under fluoride ion as catalyst is described.The reaction works especially well with nonenolizable carbonyl compounds to give the expected alkenes in high yields and, in some cases, with high stereoselectivity.Application of this methodology to an intramolecular alkenation providing a tricyclic benzocarbacephem ring system is also described.
Palladium-Catalyzed Syntheses of Aryl Polyenes
Mitsudo, Taki-aki,Fischetti, William,Heck, Richard F.
, p. 1640 - 1646 (2007/10/02)
The palladium-catalyzed arylation reaction has been employed to prepare a variety of mono- and diaryl 1,3-dienes and 1,3,5-trienes.The yields were good when electron withdrawing substituents were present in the aryl groups but only poor to fair when electron-donating groups were involved.Monoaryl dienes and trienes reacted well with all types of aryl halides to give mixed diaryl derivatives. 2-Bromostyrene reacts with phenylhexatriene to form 1,8-diphenyloctatetraene and with hexatriene to form 1,10-diphenyldecapentaene, but both only in about 15percent yield.
Additions of Carboxylic Acid Dianions to α,β-Unsaturated Carbonyl Compounds - Control of the 1,2-/1,4-Regioselectivity by Steric Substituent Effects
Mulzer, Johann,Bruentrup, Gisela,Hartz, Georg,Kuehl, Uwe,Blaschek, Ursula,Boehrer, Gerald
, p. 3701 - 3724 (2007/10/02)
Dilithium carboxylic acid dianions 1 attack α,β-unsaturated aldehydes (2) 1,2-regiospecifically with formation of the unsaturated β-hydroxy carboxylic acids 3/4.Additionally, the addition of the phenylacetate dianion 1a can be conducted to the threo-isomer with high selectivity by reversible reaction. - α,β-Enones (8) add 1 irreversibly in 1,2- and 1,4-position.Depending on the substitution pattern, the whole range from pure 1,2- to pure 1,4-adduct is covered.The influence of the 1-counterion M and of the solvent is significant; the 1,4-portion increases with the complexing effect of M and with the Lewis-basicity of the solvent.
