165277-06-5

Upstream product

• 123-73-9 trans-Crotonaldehyde 
• 80522-42-5 triisopropylsilyl trifluoromethanesulfonate 
• 123-73-9 crotonaldehyde 

Relevant academic research and scientific papers

Structure and reactivity of an isolable seven-membered-ring trans-alkene

The isolation and characterization of a trans-oxasilacycloheptene is reported. Single-crystal X-ray crystallographic studies indicate a high level of strain and deviation from ideal geometry. Reactions with several electrophiles demonstrated the nucleophilicity of the C=C double bond, affording oxasilacycloheptane and tetrahydrofuran products as single diastereomers.

Nickel-Catalyzed Enantioselective Synthesis of Pre-Differentiated Homoallylic syn- or anti-1,2-Diols from Aldehydes and Dienol Ethers

Nickel catalysis allied with cyclodiphosphazane or VAPOL-derived phosphoramidite ligands provides selective access to monoprotected vicinal diols by reductive coupling of dienol ethers and aldehydes. The observed regioselectivity is unprecedented, in that the diene reacts at the least nucleophilic and most hindered C atom that is attached to the oxygen substituent rather than at the terminal position. Notably, both syn and anti diastereomers of the products can be accessed depending on the configuration of the diene partner with usually excellent diastereo- and enantioselectivity.

Diastereoselective synthesis of seven-membered-ring trans-alkenes from dienes and aldehydes by silylene transfer

Silver-catalyzed silylene transfer to alkenes forms vinylsilacyclopropanes regioselectively. These allylic silanes undergo additions to aldehydes to form seven-membered-ring trans-alkenes with high diastereoselectivity. The high reactivity of the trans-alkenes is evidenced by their formal [1,3]-sigmatropic rearrangement reactions and the rapid additions of oxygen-hydrogen bonds across the carbon-carbon double bonds.

Regio- and stereoselective nickel-catalyzed homoallylation of aldehydes with 1,3-dienes

Ni(acac)2 catalyzes homoallylation of aldehydes with 1,3-dienes in the presence of triethylborane. Triethylborane serves as a reducing agent delivering a formal hydride to the C2 position of 1,3-dienes, thus generating a formal homoallyl anion species and enabling the novel homoallylation of aldehydes. The reaction proceeds smoothly at room temperature in the absence of any phosphane or nitrogen ligands and is highly regioselective and stereoselective for a wide variety combination of aldehydes and 1,3-dienes: e.g., isoprene and benzaldehyde combine to give a mixture of anti- and syn-1-phenyl-3-methyl-4-penten-1-ol (2.2) in a ratio of 15:1 in 90% yield. Under the conditions, sterically congested aliphatic aldehydes and ketones show low yields. In such cases, diethylzinc serves as a substitute for triethylborane and yields the expected products in good yields with similarly high regio- and stereoselectivity. 1,3-Cyclohexadiene is one exception among 24 kinds of dienes examined and undergoes allylation (not homoallylation) selectively.

Preparation and Reactions of Diorganozincs from Dienic Silyl Enol Ethers

The hydroboration of the dienic silyl enol ethers 1a-d with Et2BH produces organoboranes which are readily converted under mild conditions by a treatment with Et2Zn to the corresponding dialkylzincs 2a-d.These organometallics react after transmetallation with CuCN*2LiCl with various electrophiles affording polyfunctional silyl enol ethers of type 4.In the presence of the chiral catalyst (1R,2R)-bis(trifluoromethanesulfonamido)cyclohexane 6, the dialkylzinc 2b was added to various aldehydes leading to hydroxy silyl enol ethers of type 8 in satisfactory yields (45-77percent) and excellent enantioselectivities (85 to >96percent ee).The chiral products 8 can be oxidatively cyclized using t-BuOOH and catalytic amounts of VO(acac)2 furnishing trisubstituted tetrahydopyrans like 9a,b with high diastereoselectivity.An iodoalkoxylation of 8a affords after HI elimination and Jones oxidation the unsaturated valerolactone 13.