两种新型的钌络合物期RuH(CO)氯(PPH 3)(κ 2 -CP)(1)和[ FAC -RuH(CO)(PPH 3)(κ 3 -CNP)]氯(2)轴承不对称ñ -杂环合成了卡宾-氮-膦(CNP)并通过1 H NMR,31 P NMR和HRMS进行了表征。配合物2的结构通过单晶X射线衍射进一步确认。阴离子交换实验证明复合物2可以转化为复合物1在解决方案中。两种络合物在醇与酯的无受体脱氢偶联中显示出高催化性能,并且在对-和间-取代的苄醇和长链伯醇的催化剂负载量为1%时,酯的分离产率极佳。尽管由于空间位阻以及电子给体与钌中心的配位,一些邻位取代的苄醇显示出较低的反应性,但延长反应时间仍可获得良好的产物收率。特别地,该系统成功地实现了两种不同伯醇之间的酯的脱氢交叉偶联。
The present invention relates to: a novel dienal compound which has an aromatic odor useful for use as a compound flavor raw material or the like; and a flavor composition containing the dienal compound. The dienal compound according to the present invention is characterized by being represented by general formula (1):
(wherein R represents an alkyl group having 8 to 10 carbon atoms; and a wavy line represents a cis form, a trans form, or a mixture of a cis form and a trans form).
Symmetric esters by Tischtschenko reaction of aldehydes catalyzed by bi- and tridentate catalysts derived from catechol or gallol, trimethylaluminum and isopropanol
作者:Ilkka Simpura、Vesa Nevalainen
DOI:10.1016/s0040-4020(01)01004-3
日期:2001.12
New inexpensive aluminum-based bidentate and tridentate chelates were found to be efficient catalysts for the Tischtschenkoreaction of aldehydes. The conversion of n-butanal to n-butyl n-butyrate using catechol-derived catalysts at room temperature was complete (the yield of the butyrate was 99%) in two hours. High yields of symmetric esters were obtained in the case of n-alkyl and α-branched aliphatic
NaBrO3 combined with NaHSO3 was found to be an efficent reagent for the oxidative esterification of primaryalcohols. Thus, a variety of esters was prepared from primaryalcohols, aldehydes, and acetals in aqueous medium under mild conditions. Treatment of α,ω-diols with NaBrO3/NaHSO3 reagent afforded the corresponding lactones and/or dicarboxylic acids in fair yields.
Primaryalcohols undergo efficiently oxidative dimerization by iridiumcomplexes under air without any solvent to form esters in fair to good yields. For instance, the reaction of 1-dodecanol in the presence of [IrCl(coe)2]2 (3 mol %) at 95 °C for 15 h produced dodecyl dodecanoate in 91% isolated yield. This is the first successful Ir-catalyzed oxidative dimerization of primaryalcohols to esters using
Provided are a compound and a fragrance composition that are excellent in harmony with various other fragrance materials and can be blended to impart a natural and fresh floral feeling. The present invention provides a cyclopropane compound represented by Formula (I) and a fragrance composition containing a cyclopropane compound represented by Formula (I):
where R
1
is a methyl group and R
2
is a methyl group, or R
1
is a hydrogen atom and R
2
is an ethyl group.