72952-69-3

Upstream product

• 504-60-9 penta-1,3-diene 
• 100-52-7 benzaldehyde 
• 591-93-5 1,4-Pentadiene 
• 102820-40-6 2-(1-ethenyl-2-propenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 
• 438497-80-4 (OC(CH₃)2C(CH₃)2O)BCH₂(CH)3CH₂ 
• 613243-03-1 3-[dimethyl((E)-3'-trimethylsilanyl-prop-1'-enyl)silanyloxy]-3-phenylpropanal 
• 54962-98-0 pentadienyl lithium 
• 96-09-3 styrene oxide 
• 18269-52-8 1-trimethylsilanyl-but-3-en-2-ol 
• 72952-73-9 (E)-2,4-pentadienyltrimethylsilane 

Downstream Products

• 1189949-05-0 (E)-1-phenylhexa-3,5-dienyl acrylate 

Relevant academic research and scientific papers

Chiral Phosphoric Acid Dual-Function Catalysis: Asymmetric Allylation with α-Vinyl Allylboron Reagents

We report a dual function asymmetric catalysis by a chiral phosphoric acid catalyst that controls both enantioselective addition of an achiral α-vinyl allylboronate to aldehydes and pseudo-axial orientation of the α-vinyl group in the transition state. The reaction produces dienyl homoallylic alcohols with high Z-selectivities and enantioselectivities. Computational studies revealed that minimization of steric interactions between the alkyl groups of the diol on boron and the chiral phosphoric acid catalyst influence the orientation of α-vinyl substituent of the allylboronate reagent to occupy a pseudo-axial position in the transition state.

Cu-Catalyzed Highly Stereoselective Syntheses of (E)-δ-Vinyl-homoallylic Alcohols

Stereoselective synthesis of (E)-δ-vinyl-homoallylic alcohols was developed. Starting from α-vinyl allylboronate, Cu-catalyzed allylation of aldehydes or ketones forms secondary or tertiary δ-vinyl-homoallylic alcohols with high E-selectivities. It is pro

Remarkable rate acceleration of intramolecular Diels-Alder reaction in ionic liquids

The intramolecular Diels-Alder reaction of an ester-tethered 1,3,9-decatriene system was significantly accelerated in ionic liquids such as [emim]BF4, [bmim]BF4 and [bdmim]BF4. Under the present conditions, the IMDA reaction proceeded smoothly without the use of Lewis acid catalysts to give cis-fused bicyclic lactones in good yield with high diastereoselectivity.

Temporary silicon connection strategies in intramolecular allylation of aldehydes with allylsilanes

(Chemical Equation Presented) Three γ-(amino)silyl-substituted allylsilanes 14a-c have been prepared in three steps from the corresponding dialkyldichlorosilane. The aminosilyl group has been used to link this allylsilane nucleophile to a series of β-hydroxy aldehydes through a silyl ether temporary connection. The size of the alkyl substituents at the silyl ether tether governs the outcome of the reaction on exposure to acid. Thus, treatment of aldehyde (E)-9aa, which contains a dimethylsilyl ether connection between the aldehyde and allylsilane, with a range of Lewis and Bronsted acid activators provides an (E)-diene product. The mechanism of formation of this undesired product is discussed. Systems containing a sterically more bulky diethylsilyl ether connection react differently: thus in the presence of TMSOTf and a Bronsted acid scavenger, intramolecular allylation proceeds smoothly to provide two out of the possible four diastereoisomeric oxasilacycles, 23 (major) and 21 (minor). A diene product again accounts for the remaining mass balance in the reaction. This side product can be completely suppressed by using a sterically even more bulky diisopropylsilyl ether connection in the cyclization precursor, although this is now at the expense of a slight erosion in the 1,3-stereoinduction in the allylation products. The sense of 1,3-stereoinduction observed in these intramolecular allylations has been rationalized by using an electrostatic argument, which can also explain the stereochemical outcome of a number of related reactions. Levels of 1,4-stereoinduction in the intramolecular allylation are more modest but can be significantly improved in some cases by using a tethered (Z)-allylsilane in place of its (E)-stereoisomer. Oxidation of the major diastereoisomeric allylation product 23 under Tamao-Kumada conditions provides an entry into stereodefined 1,2-anti-2,4-syn triols 28.

Aluminum bis(trifluoromethylsulfonyl)amides: New highly efficient and remarkably versatile catalysts for C-C bond formation reactions

Superacid-derived aluminum catalysts R2AlNTf2 (2-5 mol%) are highly efficient and versatile and are suitable promoters for the allylation and pentadienylation of aldehydes, aldol reactions, aldol cross-coupling of ketones, and Michae

(E)- And (Z)-1-(Phenylsulfonyl)-4-(trimethylsilyl)-2-butenes: Synthetic Equivalents for the 1-(1,3-Butadienyl) Anion and the 1,1-(1,3-Butadienyl) Dianion

(E)- and (Z)-1-(phenylsulfonyl)-4-(trimethylsilyl)-2-butenes (7 and 8) are converted by n-BuLi to (E)- and (Z)-1-lithio-1-(phenylsulfonyl)-4-(trimethylsilyl)-2-butenes (15 and 16) with retention of initial stereochemistries. Reactions of 15 and 16 with electrophiles (protio and deuterio acids, primary, secondary, and benzyl halides, chloroformates, chlorothioformates, acid chlorides, epoxides, trialkylsilyl chlorides, and triethylgermanyl chloride) in THF or THF/HMPA give the corresponding (E)- and (Z)-1-(phenylsulfonyl)-1-substituted-4-(trimethylsilyl)-2-butenes (32) with stereochemical retention. That β,γ-unsaturated silyl sulfones 32 are formed instead of their α,β-unsaturated (conjugated) isomers are attributed to stabilizing multiple anionic and cationic hyperconjugation and to steric effects as in 29-31. Of importance in synthesis is that 32 are eliminated by TBAF at -20 to 0°C, thermally, or by column chromatography to (E)- (100 to > 93%) rather than (Z)-1-substituted-1,3-butadienes (38). Further, 32 undergo conversions by n-BuLi and various alkylating agents to (unconjugated) 1-(phenylsulfonyl)-1,1-disubstituted-4-(trimethylsilyl)-2-butenes (46) with retention of stereochemistry. Eliminations of 46 by fluoride ion, acid catalysis, or heat yield 1,1-disubstituted-1,3-butadienes (53). Silyl sulfones 7 and 8 are thus synthetic equivalents for the (E)-1-(1,3-butadienyl) anion (44) and the 1,1-(1,3-butadienyl) dianion (57). Silyl sulfones 7 and 8 also undergo efficient stereospecific intramolecular conversions by n-BuLi and α,ω-dihalides to 1,1-cycloalka-1-(phenylsulfonyl)-4-(trimethysilyl)-2-butenes (62 and 71) that are eliminated by fluoride ion, heat, or adsorption chromatography to 1,1-cycloalka-1,3-butadienes (72).

Synthetic Implications of the Reactions of Alkali-Metal Pentadienyls with Organic Electrophiles and Comments on the Nature of "Organopotassiums" Derived Using Lochmann's Base.

Pentadienyl anions derived by metallation of penta-1,4-diene with n-butyl-lithium, or of penta-1,3-diene with n-butyl-lithium - potassium tert-butoxide, react with electrophiles to produce mixtures of E- and Z-5-substituted penta-1,3-dienes and 3-substituted penta-1,4-dienes.The proportions depend, amongst other things, upon the nature of the electrophile.For simple aldehydes and ketones, for example, the proportions can vary, under otherwise identical conditions, from entirely 5-substituted product (as an E/Z mixture) with benzophenone, to predominantly (64percent) 3-substituted product with acetone.Reaction with bromocyclopentane produces almost entirely the 3-substituted product.The synthetic implications of these results are discussed.The reactions of the anions generated by the two different methods are very similar, which has prompted a discussion of the nature of the reagents, often described as organopotassiums, which are derived using Lochmann's base.

(2,4-Pentadienyl)trimethylsilane: A Useful Pentadienylation Reagent

Pentadienyllithium reacts with trimethylchlorosilane to give (2,4-pentadienyl)trimethylsilane, Me3SiCH2CH=CHCH=CH2, as the exclusive product.This silane reacts with aliphatic and aromatic aldehydes and ketones in the presence of TiCl4 in dichloromethane at -40 deg C to give, after hydrolytic workup, exclusively products of the type RR'C(OH)CH2=CHCH=CH2 in good yield.With α,β-unsaturated carbonyl compounds a TiCl4-induced Diels-Alder reaction of the dienylsilane interferes.