Amine and Titanium (IV) Chloride, Boron (III) Chloride or Zirconium (IV) Chloride-Promoted Baylis-Hillman Reactions
作者:Min Shi、Jian-Kang Jiang、Shi-Cong Cui
DOI:10.3390/61100852
日期:——
Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV) chloride, boron (III) chloride or zirconium (IV) chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give
Titanium(IV) chloride, zirconium(IV) chloride or boron trichloride and phosphine-promoted Baylis–Hillman reaction of aldehydes with α,β-unsaturated ketone
In the Baylis–Hillman reaction of aldehydes with an α,β-unsaturated ketone, the chlorinated compound 1 was obtained as the major product using tributylphosphine as a Lewis base in the presence of titanium(IV) chloride, zirconium(IV) chloride or borontrichloride in dichloromethane at <−20 °C. A plausible reaction mechanism has been proposed. Using (R)-(+)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl
Titanium(IV) chloride and oxy-compounds promoted Baylis–Hillman reaction
作者:Min Shi、Jian-Kang Jiang、Shi-Cong Cui
DOI:10.1016/s0040-4020(01)00710-4
日期:2001.8
The Baylis–Hillman reaction of aryl aldehydes with α,β-unsaturated ketones in the presence of titanium(IV) chloride can be promoted by oxy-compounds at room temperature, although they are not as effective as amines, chalcogenides, or quaternary ammonium salts. The oxy-compounds can be simple alcohols, ethers, and ketones. For aryl aldehydes having a strong electron-withdrawing group on the phenyl ring
Titanium(IV) Chloride and Quaternary Ammonium Salt Promoted Baylis−Hillman Reaction
作者:Min Shi、Yan-Shu Feng
DOI:10.1021/jo0009853
日期:2001.1.1
drastically affected by the reaction temperature and Lewis bases. When the reaction was carried out at -78 degrees C using catalytic amounts of quaternary ammoniumsalts (R4N+X-, X = Cl, Br, I) as Lewis bases, in the presence of titanium(IV) chloride, the chlorinated aldol adduct 1 was obtained as the major product. Quaternary ammoniumbromides and iodides (R4N+X-, X = Br, I) have higher catalytic activity