693803-07-5

Upstream product

• 105-45-3 acetoacetic acid methyl ester 
• 589-15-1 1-bromomethyl-4-bromobenzene 
• 117745-73-0 2-[1-(4-Bromo-phenyl)-meth-(Z)-ylidene]-3-oxo-butyric acid methyl ester 

Downstream Products

• 1251532-38-3 methyl α-(4-bromobenzyl)diazoacetate 
• 1310218-28-0 methyl (1S,5S)-1-(4-bromobenzyl)-5-(tert-butyldimethylsilyloxy)-2-oxocycloheptanecarboxylate 
• 1310218-12-2 methyl (S)-1-(4-bromobenzyl)-2-oxocycloheptanecarboxylate 

Relevant academic research and scientific papers

Catalytic Asymmetric Homologation of Ketones with α-Alkyl α-Diazo Esters

The homologation of ketones with diazo compounds is a useful strategy to synthesize one-carbon chain-extended acyclic ketones or ring-expanded cyclic ketones. However, the asymmetric homologation of acyclic ketones with α-diazo esters remains a challenge due to the lower reactivity and complicated selectivity. Herein, we report the enantioselective catalytic homologation of acetophenone and related derivatives with α-alkyl α-diazo esters utilizing a chiral scandium(III) N,N′-dioxide as the Lewis acid catalyst. This reaction supplies a highly chemo-, regio-, and enantioselective pathway for the synthesis of optically active β-keto esters with an all-carbon quaternary center through highly selective alkyl-group migration of the ketones. Moreover, the ring expansion of cyclic ketones was accomplished under slightly modified conditions, affording a series of enantioenriched cyclic β-keto esters. Density functional theory calculations have been carried out to elucidate the reaction pathway and possible working models that can explain the observed regio- and enantioselectivity.

Design, Synthesis, and Structure-Activity Relationship Study of Pyrazolones as Potent Inhibitors of Pancreatic Lipase

Pancreatic lipase (PL), a key target for the prevention and treatment of obesity, plays crucial roles in the hydrolysis and absorption of in dietary fat. In this study, a series of pyrazolones was synthesized, and their inhibitory effects against PL were

FeCl3·6H2O-catalyzed selective conjugate reduction of alkylidene-β-keto esters and alkylidene-1,3-diketones

FeCl3·6H2O/triethylsilane composite catalyst system is successfully developed for the selective conjugate reduction of carbon-carbon double bond of Michael acceptor-alkylidene-β-keto esters and alkylidene-1,3-diketones under mild rea

Catalytic Enantioselective Protonation/Nucleophilic Addition of Diazoesters with Chiral Oxazaborolidinium Ion Activated Carboxylic Acids

A new chiral Br?nsted acid derived from carboxylic acid and a chiral oxazaborolidinium ion (COBI), as an activator, is introduced. This acid was successfully applied as a catalyst for the highly enantioselective protonation/nucleophilic addition of diazoesters with carboxylic acids.

Catalytic asymmetric insertion of diazoesters into Aryl-CHO bonds: Highly enantioselective construction of chiral all-carbon quaternary centers

This paper describes a catalytic enantioselective route to synthesize functionalized all-carbon quaternary acyclic systems via a boron Lewis acid-promoted formal C-C insertion of diazoesters into aryl-CHO bonds. In the presence of chiral (S)-oxazaborolidinium cation 1d as a catalyst, the reaction proceeded in good yield (up to 83%) with good regioselectivity (up to 88:12) and excellent enantioselectivity (up to 99% ee). The synthetic potential of this method was illustrated by conversion of the products to both α-and β-amino esters.

Desymmetrizing asymmetric ring expansion of cyclohexanones with α-diazoacetates catalyzed by chiral aluminum Lewis acid

Chiral aluminum Lewis acid catalyst composed of Me3Al and 3,3′-bis(trimethylsilyl)-BINOL in a 2:1 ratio was found to promote novel catalytic asymmetric ring expansion of cyclohexanone with α-substituted α-diazoacetates to give seven-membered rings with an all-carbon quaternary center. Application of this strategy to 4-substituted cyclohexanones opened up a novel way for the catalytic desymmetrizing asymmetric construction of cycloheptanones bearing remote α,δ-chiral centers.

Cyclization of arylacetoacetates to indene and dihydronaphthalene derivatives in strong acids. Evidence for involvement of further protonation of O,O-diprotonated β-ketoester, leading to enhancement of cyclization

The chemical features, such as substrate stability, product distribution, and substrate generality, and the reaction mechanism of Bronsted superacid-catalyzed cyclization reactions of aromatic ring-containing acetoacetates (β-ketoesters) were examined in detail. While two types of carbonyl cyclization are possible, i.e., keto cyclization and ester cyclization, the former was found to take place exclusively. The reaction constitutes an efficient method to synthesize indene and 3,4-dihydronapthalene derivatives. Acid-base titration monitored with 13C NMR spectroscopy showed that the acetoacetates are fully O1,O3-diprotonated at H 0) -11. While the five-membered ring cyclization of the arylacetoacetates proceeded slowly at H0) -11, a linear increase in the rate of the cyclization was found with increasing acidity in the high acidity region of H0) -11.8 to -13.3. Therefore, the O 1,O3-diprotonated acetoacetates exhibited some cyclizing reactivity, but they are not the reactive intermediates responsible for the acceleration of the cyclization in the high acidity region. The reactive cationic species might be formed by further protonation (or protosolvation) of the O1,O3-diprotonated acetoacetates; i.e., they may be tricationic species. Thermochemical data on the acid-catalyzed cyclization of the arylacetoacetates showed that the activation energy is decreased significantly as compared with that of the related acid-catalyzed cyclization reaction of a compound bearing a single functional group, such as a ketone. These findings indicate that intervention of the trication contributes to the activation of the cyclization of arylacetoacetates in strong acid, and the electron-withdrawing nature of the O-protonated ester functionality significantly increases the electrophilicity of the ketone moiety.

Palladium-catalyzed oxidative cross-coupling reaction of arylboronic acids with diazoesters for stereoselective synthesis of (E)-α,β- diarylacrylates

A Pd-catalyzed oxidative cross-coupling reaction of arylboronic acids with α-diazoesters was achieved using molecular oxygen as the sole reoxidant, and E-α,β-diarylacrylates were obtained in good yields and >20:1 E-to-Z selectivity.