69366-49-0

Upstream product

• 925-90-6 ethylmagnesium bromide 
• 1896-62-4 (E)-benzalacetone 
• 69413-76-9 3-Ethyl-3-hydroxy-5-phenyl-(E)-4-pentensaeure 
• 100-42-5 styrene 
• 23074-36-4 2-bromobutene 
• 3152-68-9 (1E)-1-phenylpent-1-en-3-one 
• 1779-49-3 Methyltriphenylphosphonium bromide 
• 14371-10-9 (E)-3-phenylpropenal 
• 34862-94-7 (E)-1-phenyl-1-penten-3-ol 

Relevant academic research and scientific papers

Palladium-Catalyzed Regio- A nd Enantioselective Hydrosulfonylation of 1,3-Dienes with Sulfinic Acids: Scope, Mechanism, and Origin of Selectivity

Chiral sulfones are important structural motifs in organic synthesis because of their widespread use in pharmaceutical chemistry. In particular, chiral allylic sulfones have drawn particular interest because of their synthetic utility. However, enantioselective synthesis of 1,3-disubstituted unsymmetrical chiral allylic sulfones remains a challenge. In this article, we report a protocol for (R)-DTBM-Segphos/Pd-catalyzed regio- A nd enantioselective hydrosulfonylation of 1,3-dienes with sulfinic acids, which provides atom- A nd step-economical access to 1,3-disubstituted chiral allylic sulfones. The reaction occurs under mild conditions and has a broad substrate scope. Combined experimental and computational studies suggest that the reaction is initiated by a ligand-to-ligand hydrogen transfer followed by a C-S bond reductive elimination via a six-membered transition state. Steric repulsion between the olefinic C-H of the substrate and the tert-butyl group of (R)-DTBM-Segphos was found to be a key factor in the enantiocontrol.

Zinc(II)-Catalyzed Asymmetric Diels-Alder Reaction of (E)-1-Phenyl Dienes with β,γ-Unsaturated α-Ketoesters

A highly regio-, diastereo-, and enantioselective Diels-Alder reaction of β,γ-unsaturated α-ketoesters with (E)-1-phenyl dienes has been accomplished by using a stable and easily available chiral N,N′-dioxide/zinc(II) complex as catalyst. Only one isomer of the corresponding cyclohexenes with three chiral centers was obtained in good to excellent yields with excellent ee values under mild reaction conditions. The configurations of the product and chiral N,N′-dioxide/zinc(II) catalyst were identified by X-ray diffraction analysis. In addition, a possible catalytic model was proposed to explain the origin of the asymmetric induction.

Tunable phosphoramidite ligands for asymmetric hydrovinylation: Ligands par excellence for generation of all-carbon quaternary centers

α-Alkylstyrenes undergo efficient hydrovinylation (addition of ethene) in the presence of a nickel catalyst prepared from [(allyl)NiBr] 2, Na+[BAr4]- [Ar = 3,5-bis(trifluoromethyl)phenyl], and a phosphoramidite ligand giving products in excellent yields and enantioselectivities. In many cases phosphoramidites derived from achiral 2,2′-biphenol are almost as good as ligands derived from the more expensive enantiopure 1,1′-bi(2-naphthol)s. The hydrovinylation products, which carry two versatile latent functionalities, an aryl and a vinyl group, are potentially useful for the synthesis of several important natural products containing benzylic all-carbon quaternary centers. Georg Thieme Verlag Stuttgart.

Palladium-tetraphosphine complex catalysed heck reaction of vinyl bromides with alkenes: A powerful access to conjugated dienes

A wide variety of 1,3-dienes have been prepared by the Heck vinylation of vinyl bromides using [Pd(η3-C3H5)Cl] 2/cis,cis,cis-1,2,3,4-tetrakis[(diphenylphosphino)methyl] cyclopentane (Tedicyp) as the catalyst precursor. Both α- and β-substituted vinyl bromides undergo the Heck reaction with functionalised alkenes such as acrylates, enones, styrenes or a vinyl sulfone, and also with nonfunctionalised alkenes such as dec-1-ene, leading stereoselectively, in most cases, to the corresponding E- or E,E-1,3-dienes in good yields. Furthermore, this catalyst can be used at low loading for several reactions. Georg Thieme Verlag Stuttgart.

Heck reaction of vinyl bromides with alkenes in the presence of a tetraphosphine/palladium catalyst

Through the use of [PdCl(C3H5)]2- cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of vinyl bromides undergo Heck reaction with a wide variety of alkenes leading selectively to the corresponding 1,3-dienes in good yields. Furthermore, it can be used at low loading even for reactions of sterically hindered vinyl bromides.

The effect of high pressure on the diastereoselectivity of intermolecular all-carbon Diels-Alder reactions

The influence of high pressure on the diastereoselectivity of the intermolecular all-carbon Diels-Alder reaction of the phenylbutadienes 1 a- c with the dicyanoethylenes 2a-d to give the cyclohexenes 3-8 is described. The differences in activation volume, ΔΔV(≠), for the two pathways leading to cis and trans diastereomers range from - (0.7 ± 0.8) to - (6.4 ± 0.6) cm3mol-1 indicating a pressure-induced increase of diastereoselectivity in favour of the cis adducts 3a-d, 5a-d and 7b-d.

Synthesis of Isomerically Pure (E)- and (Z)-1,3-Disubstituted 1,3-Dienes

The (E)-dienes 1a - p were prepared in >98percent purity by dehydrative decarboxylation of the corresponding 4,5-unsaturated 3-hydroxycarboxylic acids 3 with dimethylformamide dimethylacetal (11).The (Z)-isomers 6a - m were obtained by stereouncontrolled