32623-19-1

Upstream product

• 32623-17-9 4-p-tolyl-4-pentenoic acid ethyl ester 
• 398142-12-6 4-(4-methylphenyl)-4-pentenoic acid 
• 4619-20-9 3-(4-methylbenzoyl)propionic acid 
• 108-88-3 toluene 
• 66520-90-9 2-(4-methylphenyl)-2-propen-1-ol 
• 128860-65-1 4-bromo-4-pentenal dimethyl acetal 
• 4294-57-9 para-methylphenylmagnesium bromide 
• 6942-61-6 ethyl 4-oxo-4-(p-tolyl)butanoate 
• 66520-91-0 2-(p-Tolyl)-prop-2-enyl vinylether 
• 36884-29-4 4-bromo-pent-4-enal 

Downstream Products

• 93176-40-0 (R)-3-(4-methylphenyl)cyclopentanone 
• 155253-42-2 (S)-3-(4-methylphenyl)cyclopentanone 
• 4999-58-0 1-methyl-4-(6-methylhepta-1,5-dien-2-yl)benzene 

Relevant academic research and scientific papers

Cobalt-catalyzed oxidative cyclization of gem-disubstituted conjugated alkenols

Aryl gem-disubstituted conjugated alkenols underwent oxidative cyclization affording 2,5,5-trisubstituted tetrahydrofurans in reasonable yields and good diastereoselectivities using the reductive termination variation of the Mukaiyama aerobic oxidative reaction. Under oxidative termination, the same alkenols produced diols and ketonic by-products via the double hydration and beta-scission competing pathways. Furthermore, the differences in alkenol reactivity under the reductive and oxidative termination conditions were investigated.

ortho-halogeno substituents effect in asymmetric cyclization of 4-aryl-4-pentenals using a rhodium catalyst

Asymmetric cyclization of 4-aryl-4-pentenals by using a cationic [Rh((R)-BINAP)]ClO4 afforded (3R)-3-substituted cyclopentanones; on the other hand, the cyclization of 4-pentenals bearing ortho-halogeno phenyl groups afforded the opposite (3S)-ones.

Asymmetric catalysis. Asymmetric catalytic intramolecular hydroacylation of 4-pentenals using chiral rhodium diphosphine catalysts

Catalysts of the type [Rh(chiral diphosphine)]+ convert 4-substituted 4-pentenals into the corresponding 3-substituted cyclopentanones with generally high turnover numbers and frequencies at 25 °C. The enantioselectivities of various substituted 4-pentenals with two chiral diphosphines have been explored. It was found that with the binap catalyst, almost complete enantioselectivity is observed for 4-pentenal substrates bearing 4-substituted tertiary substituents and for ester groups. Ketonic substituents give very high enantioselectivities. The mechanism of intramolecular hydroacylation has been explored, and it is suggested that an important consideration for obtaining high turnover frequencies is related to the acyl-alkyl reductive elimination mechanism which is inferred to occur by a process similar to ester hydrolysis. The origin of the enantioselection is discussed in terms of the interactions between the phenyl groups of the phosphine and the substituent of the pentenal.