124745-40-0

Upstream product

• 21040-45-9 Cinnamyl acetate 
• 4964-06-1 cis-1-(Trimethylstannyl)-1-propene 
• 6336-44-3 cis-1-propenylboronic acid 
• 4407-36-7 (2E)-3-phenyl-2-propen-1-ol 
• 6783-05-7 trans-2-phenylvinylboronic acid 
• 591-97-9 1-chloro-2-butene 

Relevant academic research and scientific papers

Oxime palladacycle-catalyzed Suzuki-Miyaura alkenylation of aryl, heteroaryl, benzyl, and allyl chlorides under microwave irradiation conditions

A simple new protocol for the palladium-catalyzed Suzuki-Miyaura cross-coupling of organic chlorides under microwave irradiation is presented. Deactivated aryl and heteroaryl chlorides are efficiently cross-coupled with alkenylboronic acids and potassium alkenyltrifluoroborates using the 4,4′-dichlorobenzophenone oxime-derived palladacycle 1b as precatalyst in 0.1 to 0.5 mol% palladium loading, tris(tert-butyl)phosphonium tetrafluoroborate {[HP(t-Bu)3]BF4} as ligand, tetra-n-butylammonium hydroxide as cocatalyst, and potassium carbonate as base in N,N- dimethylformamide at 130°C under microwave irradiation conditions. Under these conditions, styrenes, stilbenes, and alkenylarenes are obtained in good to high yields, and with high regio- and diastereoselectivities in only 20 min. The reported protocol is also very efficient for the regioselective alkenylation of benzyl and allyl chlorides to afford allylarenes and 1,4-dienes. Copyright

Palladium(0)-catalyzed direct cross-coupling reaction of allylic alcohols with aryl- and alkenylboronic acids

Allylic alcohols can be used directly for the palladium(0)-catalyzed allylation of aryl- and alkenylboronic acids with a wide variety of functional groups. A triphenylphosphine-ligated palladium catalyst turns out to be most effective for the cross-coupling reaction and its low loading (less than 1 mol%) leads to formation of the coupling product in high yield. The Lewis acidity of the organoboron reagents and poor leaving ability (high basicity) of the hydroxyl group are essential for the cross-coupling reaction. The reaction process is atom-economical and environmentally benign, because it needs neither preparation of allyl halides and esters nor addition of stoichiometric amounts of a base. Furthermore, allylic alcohols containing another unsaturated carbon-carbon bond undergo arylative cyclization reactions leading to cyclopentane formation. The Royal Society of Chemistry.

Palladium(0)-catalyzed direct cross-coupling reaction of allyl alcohols with aryl- and vinyl-boronic acids

Allyl alcohols can be directly used for the palladium-catalyzed allylation of aryl- and vinyl-boronic acids without the aid of a base.

Stereoselectivity of Sigmatropic Homodienyl -Hydrogen Migrations

Interactions affecting the transition state conformational preference of substituents (R1) at the migration origin have been extensively examined for a range of devirsely substituted alkenylcyclopropane substrates undegoing homodienyl -hydrogen migration.A chair cyclohexane-like transition state model (11) best rationalizes the stereoselectivity observed in these cases.Thus, the 1,2-double-bond (E)/(Z) ratio for the rearrangement products is in reasonable agreement with prediction based on ΔG deg values for R1 equatorial/axial interconversion in substitutedcyclohexanes (at least for cases where R3 = H).For systems incorporating a bulky R3 substituent, a marked increase in stereoselectivity for the (E)-olefin product is observed.In agreement with the proposed transition state model (11), bulky R2 or R4 substituents have negligible effect on the conformational preference of R1.

Substituent Rate Effects in Sigmatropic Homodienyl -Hydrogen Migrations

The small but systematic polar substituent effect on the rates of -homodienyl hydrogen migrations previously observed for the series of alkenylcyclopropane substrates (1) has been further explored through two additional substrate series (4) and (6) bearing the aryl probe at C4 and at the migration origin C1 respectively.However, negligible substituent effects were apparent at these positions.It now seems that the substituent effect originally observed at C5 reflects electronic perturbation by the substituent, rather than an inherent charge separation in the transition state for homodienyl rearrangement.The aryl group at C1 of the series (6) does, however, afford a substantial rate enhancement relative to the parent cis-1-methyl-2-vinylcyclopropane.In addition, exlusive formation of (1E, 4Z)-1-arylhexa-1,4-diene rearrangement products is observed.These kinetic and stereochemical observations are interpreted in terms of a stereoelectronically favoured equatorial conformation for the aryl group in the transition state for rearrangement.

Palladium-Catalyzed Coupling of Allylic Acetates with Aryl- and Vinylstannanes

The palladium-catalyzed reaction of allyl acetates with aryl- and vinyltin reagents gave good yields of cross-coupled products.The reaction was mild and tolerant of functionality (CO2R, OH, OSiR3, OMe) in the tin reagent.Inversion of stereochemistry at the acetate center was observed, with retention of the geometry of the olefin of the allyl group and with exclusive coupling at the primary position.Retention of geometry of the olefin in the vinyltin reagents was also observed.