Synthesis of α,β-unsaturated aldehydes and nitriles via cross-metathesis reactions using Grubbs’ catalysts
作者:Sandra M. Rountree、Sarah F.R. Taylor、Christopher Hardacre、M. Cristina Lagunas、Paul N. Davey
DOI:10.1016/j.apcata.2014.08.032
日期:2014.9
A series of α,β-unsaturated aldehydes and nitriles of significant interest in the fragrance industry have been prepared using Grubbs’ catalysts in cross-metathesis reactions of electron-deficient olefins (i.e., acrolein, crotonaldehyde, methacrolein, and acrylonitrile) with various 1-alkenes, including 1-decene, 1-octene, 1-hexene and 2-allyloxy-6-methylheptane. The latter is of particular interest
A general route to α-alkyl (E)-α,β-unsaturated aldehydes
作者:Nour Lahmar、Jamaa Aatar、Taïcir Ben Ayed、Hassen Amri、Moncef Bellassoued
DOI:10.1016/j.jorganchem.2006.03.015
日期:2006.6
Bis(trimethylsilyl)-tert-butylaldimines 3 react with aldehydes in the presence of zinc bromide at room temperature to give, after hydrolysis, the desired α-alkyl α,β-ethylenic aldehydes in good yield and with very high Estereoselectivity. The reaction was believed to proceed via the α-silyl β-siloxyimines 4.
alkyl-substituted acyclic allylic systems with a stereocenter in the allylicposition is reported. The asymmetric induction and the site selectivity are controlled in an enantio- and regioconvergent nickel-catalyzed C(sp3)−C(sp3) cross-coupling of regioisomeric mixtures of racemic α-/γ-silylated allylic halides and primary alkylzinc reagents. The silylgroup steers the allylic displacement towards the
β-Trimethylsilyl enol ethers 1 (Z) obtained from β-bromoenolethers 2 were condensed with aliphatic and aromatic aldehydes in the presence of a catalytic quantity of trimethylsilyl triflate leading to ethylenic aldehydes 3 (E) with good yields (79–90%).
Synthesis of α,β-unsaturated carbonyl compounds by successive rearrangement and peterson olefination of β′-hydroxy-α,β-epoxysilanes
作者:Fumie Sato、Youichi Tanaka、Hiroshi Kanbara
DOI:10.1039/c39830001024
日期:——
The reaction of β′-hydroxy-α,β,-expoxysilanes with boron trifluoride–diethyl ether results in rearrangement of the epoxysilane skeleton followed by Petersonolefination, leading to αβ-unsaturated carbonylcompounds.