93965-65-2

Upstream product

• 4784-77-4 (E)-1-Bromo-2-butene 
• 2043-61-0 cyclohexanecarbaldehyde 
• 18147-55-2 but-2-enyltrichlorosilane 
• 18147-55-2 (Z)-crotyltrichlorosilane 
• 31197-41-8 crotyltributylstannane 
• 35998-93-7 tri-n-butylcrotyltin 
• 4784-77-4 (E/Z)-crotyl bromide 
• 4894-61-5 trans-but-2-enyl chloride 
• 29310-15-4 (E/Z)-Crotyldimethylchlorosilane 
• 73537-46-9 (Z)-2-Butenylchlorodimethylsilane 
• 693-03-8 n-butyl magnesium bromide 
• 591-97-9 1-chloro-2-butene 
• 100-52-7 benzaldehyde 
• 1106964-40-2 1-methylprop-2-ene-1-sulfonyl chloride 

Downstream Products

• 93965-54-9 (1RS,2RS)-N-phenylmethyl-1-cyclohexyl-2-methyl-3-buten-1-amine 
• 93965-54-9 (1RS,2SR)-N-phenylmethyl-1-cyclohexyl-2-methyl-3-buten-1-amine 
• 122200-72-0 trans-1-cyclohexyl-2-methyl-1,4-butanediol 

Relevant academic research and scientific papers

Photocatalytic Generation of π-Allyltitanium Complexes from Butadiene via a Radical Strategy

The direct conversion of industrial feedstock chemicals into highly valuable fine chemical intermediates is of great appeal to the synthetic community as well as industrial applications. This study reports a conceptually new radical strategy for the photocatalytic generation of π-allyltitanium complexes from butadiene. This novel and environmentally benign strategy enables the direct three-component allylation of carbonyls with 1,3-butadiene and α-bromocarboxylates, providing rapid access to valuable homoallylic alcohols with exceptional regio- and diastereoselectivity control.

Titanocene(III)-promoted Barbier-type crotylation of carbonyl compounds

A mild, highly regio-and stereoselective method for the crotylation of aldehydes and ketones mediated/catalyzed by titanocene(III) is described. Optimized conditions permit the selective generation of γ-adducts in high yields together with high stereoselectivity, with a predominance of anti stereoisomers.

Diastereoselective chain-elongation reactions using microreactors for applications in complex molecule assembly

Diastereoselective chain-elongation reactions are important transformations for the assembly of complex molecular structures, such as those present in polyketide natural products. Here we report new methods for performing crotylation reactions and homopropargylation reactions by using newly developed low-temperature flow-chemistry technology. In-line purification protocols are described, as well as the application of the crotylation protocol in an automated multi-step sequence. Polyketides in flow: By using new low-temperature reactors, the scope of reactions conveniently performed in a flow process has been extended to encompass diastereoselective chain elongations. Various aldehydes undergo Roush crotylations and Marshall homopropargylation reactions smoothly in flow (see scheme), with incorporated in-line work-ups that drastically reduce the amount of time required for these transformations. Copyright

The catalyzed desulfinylative allylation of carbonyl compounds with alk-2-enesulfonyl chlorides and silyl alk-2-enesulfinates

Coupling up with sulfonyl chlorides: An ene reaction of alkenes with SO2·BCl3 permits the one-pot conversion of simple alkenes into b,g-unsaturated sulfonyl chlorides or sulfinic silyl esters. These compounds can then be used as nucleophilic allylating agents with aldehydes and ketones to generate the corresponding homoallylic alcohols (see scheme) with good chemo-and diastereoselectivity in the presence of a suitable catalyst and reducing agent.

Preparation of silyl substituted crotylzinc reagents and their highly diastereoselective addition to carbonyl compounds

Readily prepared β-silyl substituted crotylzinc reagents undergo highly selective allylation of carbonyl compounds leading to syn-homoallylic alcohols. The Royal Society of Chemistry.

Crotylation of aldehydes by crotyltins: Discrimination between mechanisms involving transmetallation or simple lewis acid assistance through the consideration of the stereochemistry of the corresponding homoallylic alcohols

In the reaction of crotyltins with aldehydes in the presence of metal salts, the double consideration of the syn/anti ratio of the branched homoallylic alcohols and the Z/E ratio of their linear regioisomers is proposed as a way to discriminate between a reaction mechanism involving a transmetallation step and a reaction mechanism involving simple Lewis acid activation of the aldehyde. The formation of branched syn isomers along with Z-linear isomers as major compounds is considered to be indicative of a reaction occurring under Lewis acid assistance, whereas preference for the branched anti isomers together with E-linear isomers is considered to be indicative of a transmetallation step prior to crotylation. For reactions performed in the presence of CeCl3·7H2O/NaI, the Lewis acid assistance was shown to be the exclusive or highly prevalent pathway. Moreover, in regards to the selectivity, the regiopreference depends on the nature of the crotyltin. Whereas soluble crotyltin preferentially leads to Z-linear adducts, polymer-supported crotyltin affords the syn-branched adducts probably due to a lower 1,3-metallotropy. For reactions performed in the presence of InX 3, simple Lewis acid assistance and transmetallation appear to be competitive processes; the first one is favoured with aromatic aldehydes especially in dichloromethane, whereas transmetallation appears to be prevalent with poorly reactive aldehydes especially with InBr3 in acetonitrile. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Allylation of aldehydes promoted by the cerium(III) chloride heptahydrate/sodium iodide system: The dependence of regio- and stereocontrol on the reaction conditions

The cerium(III) chloride heptahydrate/sodium iodide complex (CeCl 3·7 H2O/NaI) acts as a useful promoter in the carbon-carbon bond forming reaction by addition of allyltributylstannanes to aldehydes. The reaction of 2-butenyltributyl

Gallium-mediated allyl transfer from bulky homoallylic alcohol to aldehydes via retro-allylation: Stereoselective synthesis of both erythro- and threo-homoallylic alcohols

(Chemical Equation Presented) Retro-allylation of bulky gallium homoallylic alkoxides occurs to generate (Z)- and (E)-crotylgallium reagents stereospecifically, starting from erythro- and threo-homoallylic alcohols, respectively. The (Z)- and (E)-crotylgallium reagents immediately reacted with aromatic aldehydes to afford the corresponding erythro and threo-homoallylic alcohols, respectively.

Direct Preparation of Allylic Zirconium Reagents from Zirconocene-Olefin Complexes and Alkenes

A novel method for preparation of allylic zirconium reagents directly from 1-alkenes via zirconoceneolefin complex has been developed. Selective transfer of the hydride of zirconocene allyl hydride complex, a tautomer of zirconocene-olefin complex, to diisopropyl ketone generates the corresponding zirconocene alkoxide allyl. The allylic zirconium reagents formed effects stereoselective allylation of aldehyde at 25 °C and -78 °C to provide syn- and anti-homoallyl alcohols, respectively. The anti-isomer is formed via a six-membered chair transition state under kinetic control. The syn-selectivity can be rationalized by considering isomerization of the anti-adduct by a retroallylation process.

A highly atom efficient, solvent promoted addition of tetraallylic, tetraallenic, and tetrapropargylic stannanes to carbonyl compounds

Tetraallylic, tetraallenic, and tetrapropargylic stannanes (0.25 equiv) react with aldehydes in methanol to provide unsaturated alcohols in good to excellent yields (56-99%). These reactions proceed exclusively with allylic rearrangement for tetra(2-butenyl)tin 2b and tetra(1,2-butadienyl)-tin 16c and predominantly with allylic rearrangement for tetrapropadienyltin 16a and tetra(2-butynyl)tin 6e. Allylation reactions also proceeded smoothly with reactive ketones such as ethyl pyruvate (9a) and cyclohexanone (9b). The corresponding TFA-catalyzed reactions of dimethyl acetals 4d and 4e are regiospecific with allylic rearrangement.