- Direct synthesis of acetals by rhodium catalysed hydroformylation of alkenes in the presence of orthoformate
-
The two catalyst precursors 2 and 2 in the presence of 4 equivalents of P(OPh)3 in triethyl orthoformate as solvent and reactant, permit the low pressure hydroformylation of various alkenes into the corresponding acetals.Apart from a few low-yield by-products resulting from isomerization of the substrates, the carbonylated products obtained directly and exclusively are acetals.Keywords: Hydroformylation; Rhodium; Catalysis; Acetals
- Soulantica, K.,Sirol, S.,Koinis, S.,Pneumatikakis, G.,Kalck, Ph.
-
-
Read Online
- Anisole: A further step to sustainable hydroformylation
-
Hydroformylation, also known as the "oxo" process, is a major industrial process that employs rhodium or cobalt catalysts in solution; therefore the solvent of this process is a critical issue for its sustainability. Although several innovative solutions have been proposed recently, traditional fossil-derived solvents dominate the scenario for this reaction. In this paper, we studied a series of solvents considered more sustainable in recent ranks in the hydroformylation of a series of olefins. Anisole, a solvent with an impressive sustainability rank and very scarcely exploited in hydroformylation, proved to be an excellent alternative for this reaction.
- Delolo, Fábio G.,Dos Santos, Eduardo N.,Gusevskaya, Elena V.
-
supporting information
p. 1091 - 1098
(2019/03/12)
-
- Phosphonium-based aminophosphines as bifunctional ligands for sequential catalysis of one-pot hydroformylation-acetalization of olefins
-
A series of ionic phosphonium-based aminophosphines L1-L3 were prepared and fully characterized, in each of which the involved bifunctional moieties of the phosphine fragment and Lewis acidic phosphonium were linked together by stable chemical bonds and bridged by one N-atom. The molecular structure of the L2-ligated Rh-complex (Rh-L2) indicated that such bifunctionalities were well retained without incompatibility problems. Investigations on co-catalysis over L1-L3 showed that L3 exhibited the best sequential catalysis for both hydroformylation and acetalization. The phosphine fragment in L3 was responsible for hydroformylation together with the Rh-complex and the phosphonium acted as the Lewis acidic catalyst in charge of acetalization. The L3-Rh(acac)(CO)2 system also exhibited good generality to hydroformylation-acetalization of a wide range of olefins in different alcohols.
- Wang, Peng,Liu, Huan,Li, Yong-Qi,Zhao, Xiao-Li,Lu, Yong,Liu, Ye
-
p. 3854 - 3861
(2016/06/14)
-
- Highly effective tandem hydroformylation-acetalization of olefins using a long-life Bronsted acid-Rh bifunctional catalyst in ionic liquid-alcohol systems
-
A robust and highly effective tandem hydroformylation-acetalization of olefins using a Bronsted acid-Rh bifunctional catalyst (ARBC) in ionic liquid-alcohol systems is reported. The key feature of the ARBC is its use of a zwitterionic phosphine ligand bearing an amino acid tag. This novel ARBC shows an excellent catalytic efficiency and a long service life without a significant drop in both the hydroformylation efficiency and the acetalization efficiency or Rh loss for more than seventeen cycles. We believe that the long-term high activity and acetal selectivity mainly benefit from the synergy between the acidic active site and the Rh active site on the ARBC and the highly effective immobilization and recycling of ARBC in ionic liquid-alcohol systems due to the strong affinity of ARBC for the ionic liquid.
- Jin, Xin,Zhao, Kun,Cui, Feifei,Kong, Fangfang,Liu, Qiangqiang
-
p. 3236 - 3242
(2013/11/06)
-
- Formation of acetals under rhodium-catalyzed hydroformylation conditions in alcohols
-
Hydroformylation of terminal alkenes in alcohol solvents leads to the selective formation of the corresponding acetals. The Xantphos ligand gave the best results as well as acetal selectivities higher than 99% and linear/branched ratios of up to 52 were obtained. The scope of the reaction was studied. Acetals were found to be unreactive under hydroaminomethylation conditions. Copyright
- Diebolt, Olivier,Cruzeuil, Clement,Mueller, Christian,Vogt, Dieter
-
supporting information; experimental part
p. 670 - 677
(2012/04/23)
-
- Synthesis of thiochromans based on indirect cation pool method
-
A method for the synthesis of thiochromans based on the reactions of stilbenes and alkoxycarbenium ion pools, which were generated and accumulated by the reaction of anodically generated ArS(ArSSAr)+ with thioacetals, has been developed.
- Matsumoto, Kouichi,Ueoka, Koji,Fujie, Shunsuke,Suga, Seiji,Yoshida, Jun-ichi
-
experimental part
p. 1103 - 1119
(2009/07/05)
-
- Characterization of aroma compounds of Chinese "Wuliangye" and "Jiannanchun" liquors by aroma extract dilution analysis
-
Aroma compounds in Chinese "Wuliangye" liquor were identified by gas chromatography-olfactometry (GC-O) after fractionation. A total of 132 odorants were detected by GC-O in Wuliangye liquor on DB-wax and DB-5 columns. Of these, 126 aromas were identified by GC-mass spectrometry (MS). Aroma extract dilution analysis (AEDA) was further employed to identify the most important aroma compounds in "Wuliangye" and "Jiannanchun" liquors. The results showed that esters could be the most important class, especially ethyl esters. Various alcohols, aldehydes, acetals, alkylpyrazines, furan derivatives, lactones, and sulfur-containing and phenolic compounds were also found to be important. On the basis of flavor dilution (FD) values, the most important aroma compounds in Wuliangye and Jiannanchun liquors could be ethyl butanoate, ethyl pentanoate, ethyl hexanoate, ethyl octanoate, butyl hexanoate, ethyl 3-methylbutanoate, hexanoic acid, and 1,1-diethoxy-3-methylbutane (FD ≥ 1024). These compounds contributed to fruity, floral, and apple- and pineapple-like aromas with the exception of hexanoic acid, which imparts a sweaty note. Several pyrazines, including 2,5-dimethyl-3-ethylpyrazine, 2-ethyl-6-methylpyrazine, 2,6-dimethylpyrazine, 2,3,5-tri-methylpyrazine, and 3,5-dimethyl-2-pentylpyrazine, were identified in these two liquors. Although further quantitative analysis is required, it seems that most of these pyrazine compounds had higher FD values in Wuliangye than in Jiannanchun liquor, thus imparting stronger nutty, baked, and roasted notes in Wuliangye liquor.
- Fan, Wenlai,Qian, Michael C.
-
p. 2695 - 2704
(2007/10/03)
-
- Selective Acetalization of Aldehydes with Trialkoxystibine using Allyl Bromide
-
Trialkoxystibine has been found to be an effective reagent for selective acetalization of aldehydes with the aid of allyl bromide.
- Liao, Yi,Huang, Yao-Zeng,Zhu, Fang-Hua
-
p. 493 - 494
(2007/10/02)
-
- 2-(2,6-DIMETHYLPIPERIDINO)ACETONITRILE AS AN ACYL CARBANION EQUIVALENT
-
Reaction of lithio 2-(2,6-dimethylpiperidino)acetonitrile with alkyl halides affords monoalkylation products which are easily hydrolyzed under mild conditions to give the homogeneous aldehyde or its acetal in moderate yield.In the case of alkyl halides having an electron donating group on aromatic ring the cyclization products are obtained.
- Wakamatsu, Takeshi,Kondo, Junichi,Hobara, Satoshi,Ban, Yoshio
-
p. 481 - 484
(2007/10/02)
-