40939-59-1

Upstream product

• 149423-52-9 1,5-diphenylpentan-2-ol 
• 63877-37-2 (1E,4E)-3-methoxy-1,5-diphenyl-1,4-pentadiene 
• 38111-44-3 phenylzinc(II) bromide 
• 569672-70-4 1-(2-phenylethyl)prop-2-en-1-yl 2,2,2-trifluoro-1-(trifluoromethyl)ethyl carbonate 
• 6052-66-0 1-phenyl-3-buten-2-ol 
• 100-39-0 benzyl bromide 
• 122-78-1 phenylacetaldehyde 
• 7484-37-9 (3-phenylpropyl)triphenylphosphonium bromide 
• 5281-18-5 benzaldehyde, hydrazone 
• 1515-78-2 buta-1,3-dien-1-ylbenzene 
• 100-52-7 benzaldehyde 
• 17486-86-1 1,5-diphenylpentan-3-ol 
• 768-56-9 4-Phenylbut-1-ene 
• 17791-55-8 (1E,4E)-1,5-diphenyl-1,4-pentadien-3-ol 

Downstream Products

• 97455-11-3 (E)-β-(3-phenyl-1-propyl)styrene 
• 54833-31-7 1,5-dicyclohexylpentane 
• 1718-50-9 1,5-diphenylpentane 

Relevant academic research and scientific papers

Nickel-catalyzed hydroalkylation and hydroalkenylation of 1,3-dienes with hydrazones

Transition-metal-catalyzed hydrofunctionalization of 1,3-dienes is a useful and atom-economical method for constructing allylic compounds. Although substantial progress on hydroalkylation of dienes with stabilized carbon nucleophiles has been made, hydroalkylation of dienes with unstabilized carbon nucleophiles has remained a challenge. In this article, we report a protocol for nickel-catalyzed hydroalkylation of dienes with hydrazones, which serve as equivalents of alkyl carbon nucleophiles. In addition, we developed a protocol for hydroalkenylation of dienes with α,β-unsaturated hydrazones, providing a new method for the synthesis of 1,4-dienes. These hydroalkylation and hydroalkenylation reactions feature mild conditions and a wide substrate scope, and the utility of the reaction products is demonstrated by the preparation of an activator of soluble guanylate cyclase.

Regio- and Diastereoselective Rhodium-Catalyzed Allylic Substitution with Unstabilized Benzyl Nucleophiles

We have developed a highly regio- and diastereoselective rhodium-catalyzed allylic substitution of challenging alkyl-substituted secondary allylic carbonates with benzylzinc reagents, which are prepared from widely available benzyl halides. This process utilizes rhodium(III) chloride as a commercially available, high-oxidation state and bench-stable pre-catalyst to provide a rare example of a regio- and diastereoselective allylic substitution in the absence of an exogenous ligand. This reaction tolerates electronically diverse benzylzinc nucleophiles and an array of functionalized and/or challenging aliphatic allylic electrophiles. Finally, the configurational fluxionality of the rhodium-allyl intermediate is exploited to develop a novel diastereoselective process for the construction of vicinal acyclic ternary/ternary stereogenic centers, in addition to a cyclic ternary/quaternary derivative.

Cobalt-Catalyzed Migrational Isomerization of Styrenes

An efficient cobalt-catalyzed migrational isomerization of styrenes was developed using the thiazoline iminopyridine (TIP) ligand. This reaction is operationally simple and atom-economical using readily available starting materials to access trisubstituted alkenes. Even when using a 0.1 mol % catalyst loading, the reaction could be conducted in neat and completed in 1 h with excellent conversion and high E stereoselectivity.

Tritiodefluorination of alkyl C–F groups

A straightforward methodology of fluorine substitution by tritium/deuterium is reported. The described method is selective towards the F─C (sp3) group and leaves both the aromatic F─C (sp2) and F2─C (sp3) moieti

Nickel-Catalyzed Regioselective Hydrobenzylation of 1,3-Dienes with Hydrazones

Hydroalkylation of unsaturated hydrocarbons with unstabilized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far have mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydrobenzylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acting as both the sources of unstabilized carbanion equivalent and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.

Simple and highly Z-selective ruthenium-based olefin metathesis catalyst

A one-step substitution of a single chloride anion of the Grubbs-Hoveyda second-generation catalyst with a 2,4,6-triphenylbenzenethiolate ligand resulted in an active olefin metathesis catalyst with remarkable Z selectivity, reaching 96% in metathesis homocoupling of terminal olefins. High turnover numbers (up to 2000 for homocoupling of 1-octene) were obtained along with sustained appreciable Z selectivity (>85%). Apart from the Z selectivity, many properties of the new catalyst, such as robustness toward oxygen and water as well as a tendency to isomerize substrates and react with internal olefin products, resemble those of the parent catalyst.

Regio- and enantiospecific rhodium-catalyzed arylation of unsymmetrical fluorinated acyclic allylic carbonates: Inversion of absolute configuration

The transition metal-catalyzed allylic substitution with unstabilized carbon nucleophiles represents an important cross-coupling reaction for the construction of ternary carbon stereogenic centers. We have developed a new regio- and enantiospecific rhodium-catalyzed allylic alkylation of acyclic unsymmetrical chiral nonracemic allylic alcohol derivatives with aryl zinc bromides. This study demonstrates that the hydrotris(pyrazolyl)borate rhodium catalyst and zinc(II) halide salt are crucial for efficiency, while the addition of lithium bromide to the catalyst is necessary for obtaining optimal regiospecificity. The stereochemical course of this reaction was established through the synthesis of (S)-ibuprofen, which demonstrated that the alkylation proceeds with net inversion of absolute configuration consistent with direct addition of the nucleophile to the metal center followed by reductive elimination. Copyright

New mixed phosphonate esters by transesterification of pinacol phosphonates and their use in aldehyde and ketone coupling reactions with nonstabilized phosphonates

Alkylpinacol phosphonates were prepared by rhodium-catalyzed olefin hydrophosphorylation, and attempted α-deprotonation of the pinacol derived alkyl phosphonates resulted in ring cleavage. The propensity of the alkylpinacol phosphonates to undergo ring opening was exploited to prepare phosphonic acid monomethyl esters in high yield by transesterification in acidulated methanol. Esterification and alkylation with aldehydes or ketones gave β-hydroxy mixed phosphonate esters. tert-Butyl and benzylic phosphonate ester protective groups were introduced to improve the efficiency and functional group compatibility of β-hydroxy phosphonate saponification. The β-hydroxy phosphonic acid monomethyl esters were dehydrated with diisopropylcarbodiimide, which gave oxaphosphetane intermediates that collapse to an olefin. The overall reaction sequence complements the arsenal of Horner-Wadsworth-Emmons-type coupling reactions.

Insertion of isocyanide into metal-carbon bonds of alkylchloro(pentamethylcyclopentadienyl)niobium- and -tantalum complexes - see abstract

Methylation of NbCp*Cl2Me2 using excess ZnMe2 gives NbCp*CiMe3 (1) which has been found to exhibit a Berry pseudorotation process on the NMR time scale (log A = 12.2 ± 0.3, E(a) = 12.2 ± 0.4 kcal · mol-1, ΔH≠ = 11.6 ± 0.4 kcal · mol-1, ΔS(≠) = -4.4 ± 1.3 e.u., ΔG(≠298K) = 12.9 kcal · mol-1). Alternatively, lithium dimethylamide reacts with NbCp*Cl2Me2 to form NbCp*Me2(NMe2)2 (2) which decomposes in solution under the elimination of methane to give the (dimethylamido)methylazaniobacyclopropane derivative NbCp*Me(NMe2)(η2-CH2NMe) (3). Reaction of NbCp* Cl2Me2 with 1 equiv. of 2,6-Me2C6H3NC results in a double methyl group migration to give the dichloroazaniobacyclopropane complex [NbCp*Cl2{η2-CMe2N(2,6-Me2C6H3)}] (4). Dialkyldichloro complexes TaCp*Cl2R2 [Cp* = η5-C5Me5; R = CH2SiMe3 (5), CH2CMe2Ph (6), CH2CMe3 (7), CH2C6H5 (8)] were obtained by treating TaCp*Cl4 with the requisite amounts of the appropriate alkylating agents. Reactions of the dialkyldichloro complexes TaCp*Cl2R2 (5-8) with 1 equiv. of 2,6-Me2C6H3NC resulted in migration of only one of the two alkyl groups to give (alkyl)dichloro(η2-iminoacyl) complexes [TaCp*Cl2R{η2-C(R)=NAr}] [Ar = 2,6-Me2C6H3; R = CH2SiMe3 (9), CH2CMe2Ph (10), CH2CMe3 (11), CH2C6H5 (12)]. The molecular structure of complex 10 has been determined by X-ray diffraction analysis. The η2-iminoacyl complexes 9-12 decompose in [D6]benzene or n-hexane solutions to give [TaCp*Cl2{N(2,6-Me2C6H3)}] and the corresponding trans or cis olefins R'-CH=CH-CH2-R' [R' = SiMe3 (9o), CMe2Ph (10o), CMe3 (11o), C6H5 (12o)]. A mechanism for this reaction is proposed. All the new compounds have been characterized by IR spectrophotometry, 1H- and 13C{1H}-NMR spectroscopy, and elemental analysis.