72681-08-4

Upstream product

• 36805-43-3 ethyl (E)-3-methyl-5-phenylpent-2-enoate 
• 72681-02-8 (Z)-3-Methyl-5-phenyl-2-penten-1-ol 
• 107647-43-8 (E)-3-methyl-5-phenylpent-2-enoic acid methyl ester 
• 100-42-5 styrene 
• 67753-90-6 9-phenethyl-9-bora-bicyclo[3.3.1]nonane 
• 3277-89-2 phenethylmagnesium bromide 
• 2550-26-7 4-Phenyl-2-butanone 
• 100-39-0 benzyl bromide 
• 122135-86-8 ethyl (Z)-5-phenyl-3-(trifluoromethylsulfonyloxy)pent-2-enoate 
• 17071-29-3 ethyl 3-oxo-5-phenylpentanoate 

Downstream Products

• 141244-65-7 1-hydroxy-3-methyl-5-phenyl-2-pentene(β-acetoxy)ethyl sulfinate 
• 55066-48-3 3-methyl-5-phenylpentan-1-ol 
• 107647-42-7 trans-3-Methyl-5-phenyl-2-pentenal 
• 41927-33-7 (S)-(-)-3-methyl-5-phenylpentan-1-ol 
• 942416-33-3 (R)-(+)-3-methyl-5-phenylpentanaldehyde 
• 942416-34-4 (S)-(-)-3-methyl-5-phenylpentanaldehyde 
• 1068660-23-0 (E)-2,2,2-trifluoro-N-(n-hexyl)acetimidic acid 3-methyl-5-phenylpent-2-enyl ester 
• 960060-45-1 (E)-2,2,2-trifluoro-N-(4-methoxyphenyl)acetimidic acid 3-methyl-5-phenyl-pent-2-enyl ester 
• 1238945-05-5 (E)-methyl (3-methyl-5-phenylpent-2-en-1-yl) carbonate 
• 1332864-74-0 (E)-(tert-butyl) 1-(3-methyl-5-phenylpent-2-enyl)hydrazinecarboxylate 
• 1332865-03-8 tert-butyl 2-(3-methyl-5-phenylpent-1-en-3-yl)diazenecarboxylate 
• 1332864-73-9 C₂₅H₂₄Cl₄N₂O₄ 
• 1334681-11-6 C₁₂H₁₅F 
• 1334680-93-1 (+/-)-(3-fluoro-3-methylpent-4-en-1-yl)benzene 

Relevant academic research and scientific papers

Visible-Light Mediated Hydrosilylative and Hydrophosphorylative Cyclizations of Enynes and Dienes

Described herein is a visible-light mediated intermolecular radical cyclization approach to access heterocycles. Heteroatom radicals, such as silicon and phosphorus atom radicals, were generated via direct hydrogen atom abstraction by the photoexcited catalyst species with hydro-silanes and phosphine oxides. The radical addition/cyclization/HAT (hydrogen atom transfer) reaction sequences of 1,6-enynes and 1,6-dienes were highly efficient delivering the desired heterocycles in good yields.

Gold-Catalyzed Asymmetric Thioallylation of Propiolates via Charge-Induced Thio-Claisen Rearrangement

A gold(I)-catalyzed enantioselective thioallylation of propiolates with allyl sulfides is described. The key mechanistic element is a sulfonium-induced Claisen rearrangement which helps minimize the allyl dissociation and render higher enantioselectivity. This protocol features remarkable scope of the allyl moiety, allowing enantiocontrolled synthesis of all-carbon quaternary centers, and exhibits exceptional functional group compatibility with many Lewis bases and π-bonds. This intermolecular variant of Claisen rearrangement forges both C-S and C-C bonds concomitantly, providing efficient access to interesting optically active organosulfur compounds which can be transformed further through the vinyl sulfide as a functional handle. The rate of the reaction was zeroth order with respect to allyl sulfides, which suggested a reversible inhibition, providing a resting state for the catalyst. The Hammett plot displayed a correlation with σp values, suggesting a turnover-limiting sigmatropic rearrangement where decreased electron-density on sulfur accelerated the rearrangement.

Highly Selective and Catalytic Generation of Acyclic Quaternary Carbon Stereocenters via Functionalization of 1,3-Dienes with CO2

The catalytic asymmetric functionalization of readily available 1,3-dienes is highly important, but current examples are mostly limited to the construction of tertiary chiral centers. The asymmetric generation of acyclic products containing all-carbon quaternary stereocenters from substituted 1,3-dienes represents a more challenging, but highly desirable, synthetic process for which there are very few examples. Herein, we report the highly selective copper-catalyzed generation of chiral all-carbon acyclic quaternary stereocenters via functionalization of 1,3-dienes with CO2. A variety of readily available 1,1-disubstituted 1,3-dienes, as well as a 1,3,5-triene, undergo reductive hydroxymethylation with high chemo-, regio-, E/Z-, and enantioselectivities. The reported method features good functional group tolerance, is readily scaled up to at least 5 mmol of starting diene, and generates chiral products that are useful building blocks for further derivatization. Systemic mechanistic investigations using density functional theory calculations were performed and provided the first theoretical investigation for an asymmetric transformation involving CO2. These computational results indicate that the 1,2-hydrocupration of 1,3-diene proceeds with high π-facial selectivity to generate an (S)-allylcopper intermediate, which further induces the chirality of the quaternary carbon center in the final product. The 1,4-addition of an internal allylcopper complex, which differs from previous reports involving terminal allylmetallic intermediates, to CO2 kinetically determines the E/Z- and regioselectivity. The rapid reduction of a copper carboxylate intermediate to the corresponding silyl-ether in the presence of Me(MeO)2SiH provides the exergonic impetus and leads to chemoselective hydroxymethylation rather than carboxylation. These results provide new insights for guiding further development of asymmetric C-C bond formations with CO2

Rearrangement Reactions Leading to Optically Active α,α-Disubstituted Primary Allylamines

Synthetic routes to α,α-disubstituted allylamines have been examined. Racemic compounds were conveniently prepared by thermal Overman rearrangements of primary allylic alcohols with trisubstituted double bonds, but rearrangement of these substrates using

Copper-catalyzed enantioselective allylic cross-coupling with alkylboranes

Abstract We have presented full details of our work on alkylboranes, which we have introduced as new reagents for copper-catalyzed SN2′-type enantioselective allylic substitutions. The copper catalysis delivered enantioenriched chiral products containing tertiary or quaternary carbon stereogenic centers branched with functionalized sp3-alkyl groups. The wide availability of alkylboranes via the established alkene hydroboration reaction is an attractive feature of these transformations. Various functional groups are tolerated in the substrates. A reaction pathway involving addition-elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed.

Construction of quaternary stereogenic carbon centers through copper-catalyzed enantioselective allylic cross-coupling with alkylboranes

A combination of an in situ generated chiral CuI/DTBM-MeO-BIPHEP catalyst system and EtOK enabled the enantioselective SN2'-type allylic cross-coupling between alkylborane reagents and γ,γ- disubstituted primary allyl chlorides with enantiocontrol at a useful level. The reaction generates a stereogenic quaternary carbon center having three sp 3-alkyl groups and a vinyl group. This protocol allowed the use of terminal alkenes as nucleophile precursors, thus representing a formal reductive allylic cross-coupling of terminal alkenes. A reaction pathway involving addition/elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed.

An oxidative [2,3]-sigmatropic rearrangement of allylic hydrazides

The development of an efficient oxidative [2,3]-sigmatropic rearrangement of allylic hydrazides, via singlet N-nitrene intermediates, is reported. The requisite allylic hydrazide precursors are readily prepared and undergo smooth sigmatropic rearrangement

Enantioselective synthesis of allylboronates bearing a tertiary or quaternary B-substituted stereogenic carbon by NHC-Cu-catalyzed substitution reactions

Allylic substitutions that afford α-substituted allylboronates bearing B-substituted tertiary or quaternary carbon stereogenic centers are presented. C-B bond-forming reactions, catalyzed by chiral bidentate Cu-NHC complexes, are performed in the presence of commercially available bis(pinacolato)diboron. Transformations proceed in high yield (up to >98%) and site selectivity (>98% SN2′), and in up to >99:1 enantiomer ratio. Trans- or cis-disubstituted alkenes can be used; alkyl- (linear as well as branched) and aryl-trisubstituted allylic carbonates serve as effective substrates. Allylboronates that bear a quaternary carbon center are air-stable and can be easily purified by silica gel chromatography; in contrast, secondary allylboronates cannot be purified in the same manner and are significantly less stable. Oxidation of the enantiomerically enriched products furnishes secondary or tertiary allylic alcohols, valuable small molecules that cannot be easily obtained in high enantiomeric purity by alternative synthesis or kinetic resolution approaches.

The asymmetric aza-claisen rearrangement: development of widely applicable pentaphenylferrocenyl palladacycle catalysts

Systematic studies have been performed to develop highly efficient catalysts for the asymmetric aza-Claisen rearrangement of trihaloacetimidates. Herein, we describe the stepwise development of these catalyst systems involving four different catalyst generations finally resulting in the development of a planar chiral pentaphenylferrocenyl oxazoline palladacycle. This complex is more reactive and has a broader substrate tolerance than all previously known catalyst systems for asymmetric aza-Claisen rearrange-ments. Our investigations also reveal that subtle changes can have a big impact on the activity. With the enhanced catalyst activity, the asymmetric aza-Claisen rearrangement has a very broad scope: the methodology not only allows the formation of highly enantioenriched primary allylic amines, but also secondary and tertiary amines; al-lylic amines with N-substituted quaternary stereocenters are conveniently accessible as well. The reaction conditions tolerate many important functional groups, thus providing stereoselective access to valuable functionalized building blocks, for example, for the synthesis of unnatural amino acids. Our results suggest that face-selective olefin coordination is the enantioselectivitydetermining step, which is almost exclusively controlled by the element of planar chirality.

Asymmetric catalysis in fragrance chemistry: a new synthetic approach to enantiopure Phenoxanol, Citralis and Citralis Nitrile

A new approach to the synthesis of the single stereomers of the fragrances Phenoxanol, Citralis and Citralis Nitrile is reported. The key step of the synthesis is the asymmetric hydrogenation of (Z)- or (E)-3-methyl-5-phen