24254-65-7

Upstream product

• 623-43-8 crotonic acid methyl ester 
• 673-41-6 p-chlorobenzenediazonium tetrafluoroborate 
• 67-56-1 methanol 
• 50-00-0 formaldehyd 
• 1712-70-5 1-chloro-4-(1-methylethenyl)-benzene 
• 201230-82-2 carbon monoxide 
• 1989-25-9 4-chlorocumyl alcohol 
• 99-91-2 para-chloroacetophenone 
• 96-32-2 bromoacetic acid methyl ester 

Relevant academic research and scientific papers

Development of efficient palladium catalysts for alkoxycarbonylation of alkenes

Herein, we report a general and efficient Pd-catalysed alkoxycarbonylation of sterically hindered and demanding olefins including a variety of tri-, tetra-substituted and 1,1-disubstituted alkenes. In the presence of 1,3-bis(tert-butyl(pyridin-2-yl)phosphanyl)propane L3 or 1,4-bis(tert-butyl(pyridin-2-yl)phosphanyl)butane L4 the desired esters are obtained in good yields and selectivities. Similar transformation is obtained using tertiary ether as showcased in the carbonylation of MTBE to the corresponding linear ester in high yield and selectivity.

Palladium-Catalyzed Carbonylation of sec- and tert-Alcohols

A general palladium-catalyzed synthesis of linear esters directly from sec- and tert-alcohols is described. Compared to the classic Koch–Haaf reaction, which leads to branched products, this new transformation gives the corresponding linear esters in high yields and selectivity. Key for this protocol is the use of an advanced palladium catalyst system with L2 (pytbpx) as the ligand. A variety of aliphatic and benzylic alcohols can be directly used and the catalyst efficiency for the benchmark reaction is outstanding (turnover number up to 89 000).

Benzene-based diphosphine ligands for alkoxycarbonylation

The invention relates to benzene-based diphosphine ligands for alkoxycarbonylation. Specifically, the invention relates to compounds of formula (I), where m and n are each independently 0 or 1; R1, R2, R3, R4 are each independently selected from -(C1-C12)-alkyl, -(C3-C12)-cycloalkyl, -(C3-C12)-heterocycloalkyl, -(C6-C20)-aryl, -(C3-C20)-heteroaryl; at least one of the R1, R2, R3, R4 radicals is a -(C3-C20)-heteroaryl radical; and to the use thereof as ligands in alkoxycarbonylation.

Regioselective Pd-Catalyzed Methoxycarbonylation of Alkenes Using both Paraformaldehyde and Methanol as CO Surrogates

In recent years, considerable effort has focused on the development of novel carbonylative transformations using CO surrogates. Consequently, toxic CO gas can be replaced by more convenient inorganic or organic carbonyl compounds. Herein, the first regioselective methoxycarbonylation of alkenes with paraformaldehyde and methanol as CO substitutes is reported. This new procedure is applicable to a series of alkenes in the presence of a palladium catalyst under relatively mild conditions and is highly atom efficient.

Highly regioselective anti-markovnikov palladium-borate-catalyzed methoxycarbonylation reactions: Unprecedented results for aryl olefins

(Chemical Equation Presented) A general, highly efficient and regioselective methoxycarbonylation, by means of a palladium-salicylicborate- catalyzed protocol, of terminal alkyl and aryl olefins is described. The substrates include aliphatic alkenes, allylbenzenes, and styrene derivatives. The yields are very good (60-92%) and the regioselectivity, in favor of the linear ester, is up to quantitative - unprecedented in the case of styrenes.

Steric, Polar, and Resonace Effects in Reactivity and Regioselectivity of Aryl Radical Addition to α,β-Unsaturated Carbonyl Compounds

Free-radical decomposition of diazonium salts by titanous salts in the presence of olefins conjugated with carbonyl groups leads to reductive arylation or arylation and diazo coupling of the radical adduct, depending on the orientation of the aryl radical addition (β or α).The absolute rate constants of the addition (107 - 108 M-1s-1 at 5 deg C) were determined by comparison with the rate of the iodine abstraction by aryl radicals from isopropyl iodide.The obtained data of the addition rates to the β position correlate well with the Es steric parameters.The influence of the resonace stabilization of the radical adduct on the reactivity can be significant, but the regioselectivity of the addition is mainly determined by steric effects.The different fate of the α- and β-radical adducts are discussed on the basis of their different polar character.