3156-07-8

Upstream product

• 4371-02-2 2-methyl-2-phenylmalonic acid 
• 525-06-4 diphenyl ketene 
• 32346-08-0 (1-methoxy-2-phenylprop-1-enyloxy)trimethylsilane 
• 25145-43-1 2-phenylpropionyl chloride 
• 3893-35-4 1-diazo-1-phenyl-2-propanone 
• 22293-10-3 (1-diazoethyl)benzene 
• 60-29-7 diethyl ether 
• 71506-74-6 2-chloro-2-phenyl-propionyl chloride 
• 74097-41-9 trans-3,5-dihydro-3,5-dimethyl-3,5-diphenyl-4H-pyrazol-4-one 
• 492-37-5 hydratropic acid 
• 31508-44-8 2-phenylpropionic acid methyl ester 
• 515-30-0 2-phenyllactic acid 
• 101-41-7 benzeneacetic acid methyl ester 

Downstream Products

• 40195-51-5 2,4-dimethyl-2,4-diphenyl-cyclobutane-1,3-dione 
• 65359-73-1 4-phenyl-penta-2,3-dienoic acid ethyl ester 
• 5717-44-2 α,γ-Dimethyl-γ-phenyl-allencarbonsaeure-ethylester 
• 38701-09-6 2,3-pentadienoic acid, 2-ethyl-4-phenyl-, ethyl ester 
• 117760-33-5 (+/-)-2-phenylpropionic acid vinyl ester 
• 103185-03-1 1-(4-methoxyphenyl)-2-phenyl-2-propen-1-one 
• 97234-80-5 (Z)-2-phenyl-3-trimethylsilyloxy-2-heptene 
• 31508-44-8 2-phenylpropionic acid methyl ester 
• 88641-61-6 2-phenylpropionic butyl ester 
• 117760-34-6 1-methylvinyl 2-phenylpropanoate 
• 117760-43-7 2,2-Dimethyl-6-phenyl-heptane-3,5-dione 
• 117760-35-7 1-t-butylvinyl 2-phenylpropanoate 
• 155397-68-5 4-Methyl-2-phenyl-5-hexen-3-on 
• 127302-44-7 (S)-5-phenyl-1-hexen-4-one 

Relevant academic research and scientific papers

Construction of All-Carbon Quaternary Stereocenters via Sequential Photoactivation/Isothiourea Catalysis

Highly enantioselective [4 + 2] cyclizations of azadienes with in situ generated ketenes were developed through sequential visible-light photoactivation/isothiourea catalysis, which offers a novel approach for the creation of all-carbon quaternary stereoc

Palladium-Catalyzed Asymmetric [8+2] Dipolar Cycloadditions of Vinyl Carbamates and Photogenerated Ketenes

Higher-order cycloadditions, particularly [8+2] cycloadditions, are a straightforward and efficient strategy for constructing significant medium-sized architectures. Typically, configuration-restrained conjugated systems are utilized as 8π-components for

Forming All-Carbon Quaternary Stereocenters by Organocatalytic Aminomethylation: Concise Access to β2,2-Amino Acids

The asymmetric synthesis of β2,2-amino acids remains a formidable challenge in organic synthesis. Here a novel organocatalytic enantioselective aminomethylation of ketenes with stable and readily available N,O-acetals is reported, providing β2,2-amino esters bearing an all-carbon quaternary stereogenic center in high enantiomeric ratios with a catalytic amount of chiral phosphoric acid. Typically, this transformation probably proceeds through an asymmetric counter-anion-directed catalysis. As a result, a concise, practical, and atom-economic protocol toward rapidly access to β2,2-amino acids has been developed.

A photoinduced Wolff rearrangement/Pd-catalyzed [3+2] cycloaddition sequence: An unexpected route to tetrahydrofurans

A novel sequential reaction that combines a visible light-induced Wolff rearrangement of α-diazoketones and a Pd-catalyzed [3+2] cycloaddition of vinyl cyclopropanes with the resulting ketenes is described in this work. Selective O-allylic alkylation was observed over C-allylic alkylation, which unexpectedly led to a series of highly functionalized tetrahydrofurans with high efficiency (20 examples, 58-99% yields).

Synthesis of Chiral Esters via Asymmetric Wolff Rearrangement Reaction

The first asymmetric Wolff rearrangement reaction that directly converts α-diazoketones into broadly useful chiral α,α-disubstituted carboxylic esters with high enantioselectivities (up to 97.5:2.5 er) is reported. The cascade reaction proceeds through the seamless combination of visible-light-induced formation of the ketene intermediate and asymmetric ketene esterification using a readily available benzotetramisole-type catalyst.

Addition-Rearrangement of Ketenes with Lithium N- tert-Butanesulfinamides: Enantioselective Synthesis of α,α-Disubstituted α-Hydroxycarboxylic Acid Derivatives

Addition of the lithium salts of chiral N-substituted tert-butanesulfinamides to ketenes and subsequent silylation initiates stereoselective [2,3]-rearrangement, which affords enantioenriched α,α-disubstituted α-sulfenyloxy carboxamides through a reaction

Stereo- and Chemodivergent NHC-Promoted Functionalisation of Arylalkylketenes with Chloral

Stereo- and chemodivergent enantioselective reaction pathways are observed upon treatment of alkylarylketenes and trichloroacetaldehyde (chloral) with N-heterocyclic carbenes, giving selectively either β-lactones (up to 88:12 dr, up to 94% ee) or α-chloroesters (up to 94% ee). Either 2-arylsubstitution or an α-branched iPr alkyl substituent within the ketene favours the chlorination pathway, allowing chloral to be used as an electrophilic chlorinating reagent in asymmetric catalysis.

Origins of diastereoselectivity in lewis acid promoted ketene-alkene [2 + 2] cycloadditions

A detailed analysis of a Lewis acid promoted ketene-alkene [2 + 2] cycloaddition is reported. The studies have led to a rationalization for an observed inversion of diastereoselectivity between thermally induced and Lewis acid promoted ketene-alkene [2 + 2] cycloadditions. The model is supported with both experimental and computational results.

NHC-promoted asymmetric β-lactone formation from arylalkylketenes and electron-deficient benzaldehydes or pyridinecarboxaldehydes

A chiral NHC catalyzes the asymmetric formal [2 + 2] cycloaddition of alkylarylketenes with both electron-deficient benzaldehydes and 2- and 4-pyridinecarboxaldehydes to generate stereodefined β-lactones. In the benzaldehyde series, optimal product diastereo- and enantiocontrol is observed using 2-nitrobenzaldehyde (up to 93:7 dr (syn:anti) and 93% ee). Substituted 2- and 4-pyridinecarboxaldehydes are also tolerated in this process, generating the corresponding β-lactones in good yield and enantioselectivity, although the diastereocontrol in these processes is highly dependent upon the aldehyde substitution. These processes are readily scalable, allowing multigram quantities of the β-lactone products to be prepared. Derivatization of these products, either through ring opening into the corresponding stereodefined β-hydroxy and β-amino acid derivatives without loss of stereochemical integrity or via cross-coupling, is demonstrated.

Lewis acid-promoted ketene-alkene [2 + 2] cycloadditions

Described are the first examples of ketene-alkene [2 + 2] cycloadditions promoted by Lewis acids. Notable features of this method include (1) substantial rate acceleration relative to traditional thermal reactions, (2) good diastereoselectivities and yields for the formation of the cyclobutanone products, and (3) inverse diastereoselectivity compared with related thermal cycloadditions for many examples. These studies not only provide access to synthetically versatile cyclobutanones that cannot be prepared by traditional thermal cycloadditions but also address important mechanistic questions regarding ketene-alkene [2 + 2] cycloaddition reactions.