140439-76-5

Upstream product

• 504-61-0 (E)-but-2-enol 
• 1571-08-0 methyl 4-formylbenzoate 
• 4784-77-4 (E/Z)-crotyl bromide 
• 4894-61-5 trans-but-2-enyl chloride 
• 6908-41-4 4-(methoxycarbonyl)benzyl alcohol 
• 106-99-0 buta-1,3-diene 
• 66534-32-5 α,α-diisopropyl-β-methylhomoallylic alcohol 
• 123-11-5 4-methoxy-benzaldehyde 

Relevant academic research and scientific papers

Carbonyl allylations by 3-halopropenes or 2-propenyl mesylate with tin(IV) chloride and tetrabutylammonium iodide

2-Propenyl tin species, prepared from 3-halopropenes or 2-propenyl mesylate with tin(IV) chloride and tetrabutylammonium iodide in dichloromethane, causes nucleophilic addition to aldehydes to produce the corresponding homoallylic alcohols.

Iridium-catalyzed hydrohydroxyalkylation of butadiene: Carbonyl crotylation

Exposure of alcohols 1a-1i to butadiene in the presence of a cyclometallated iridium catalyst derived from allyl acetate, 4-methoxy-3-nitrobenzoic acid and 2,2′-bis(diphenylphosphino)biphenyl (BIPHEP) results in hydrogen transfer to generate aldehyde-allyliridium pairs, which engage in C-C coupling to form products of carbonyl crotylation. Under related conditions using 1,4-butanediol as hydrogen donor, butadiene reductively couples to aldehydes 2e-2g and 2i to furnish carbonyl crotylation products 3e-3g and 3i. Thus, butadiene-mediated carbonyl crotylation occurs with equal facility from the alcohol or aldehyde oxidation level with complete levels of branched regioselectivity.

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.

A novel preparation of allylic trichlorotins from α,α-diisopropylhomoallylic alcohols and its application to carbonyl allylations

α,α-Diisopropylhomoallylic alcohols react with tin(II) chloride and NCS in CH2Cl2 at -40 °C to -60 °C to produce allylic tins and diisopropyl ketone, and the allylic tins in situ cause nucleophilic addition to aldehydes to afford α-s

Regio- and diastereocontrol in carbonyl allylation by 1-halobut-2-enes with tin(II) halides

Regio- and diastereoselective carbonyl allylations of 1-halobut-2-enes with tin(II) halides are described. Tin(II) bromide in a dichloromethane- water biphasic system is an effective reagent for unusual α-regioselective carbonyl allylation of 1-bromobut-2

Palladium-catalyzed carbonyl allylation by allylic alcohols with SnCl2

Allylic alcohols can be applied to carbonyl allylation via the formation of π-allylpalladium complexes, using palladium as catalyst and SnCl2 as a reducing agent. This reaction has chemoselectivity: The reactivity order of allylating agents is allylic carbonate > allylic alcohol > allylic acetate, and that of carbonyl compounds is aldehyde > ketone. High regioselcction was observed in polar solvents such as DMF, DMI, and DMSO; carbonyl compounds apparently attacked the more substituted allylic position of π-allylpalladium complexes to afford only one regioisomer. Diastereocontrol in the carbonyl allylation of aromatic aldehydes by (E)-2-butenol was achieved by the choice of polar solvents; use of DMSO at 25 °C led to syn selection, while anti selection was found at -10 °C in THF. The addition of H2O in any solvent accelerated the carbonyl allylation and enhanced both regioselectivity and the diastereoselectivity. Anti selection in DMF, DMI, and THF-H2O can be explained by the chair form of the six-membered cyclic transition state, while syn selection in DMSO allows us to propose an acyclic antiperiplanar transition state. An NMR spectroscope investigation demonstrated that the actual allylating agent in dry medium was allyltrichlorotin: 1H, 13C, and 119Sn NMR spectra of the reaction of allyl alcohol with PdCl2(PhCN)2-SnCl2 in DMF-d7. corresponded to those of the reaction of allyl chloride with PdCl2(PhCN)2-SnCl2 in DMF-d7.