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1.
Iodination of primary, secondary, allylic, and benzylic alcohols giving their corresponding iodides was achieved with ZrCl4/NaI in anhydrous CH3CN with excellent yields and selectivities.  相似文献   

2.
By using a dimeric ruthenium complex in combination with tert‐butyl hydrogen peroxide (TBHP) as stoichiometric oxidant, a mild and efficient protocol for the oxidation of secondary benzylic alcohols was obtained, thereby giving the corresponding ketones in high yields within 4 h. However, in the oxidation of aliphatic alcohols, the TBHP protocol suffered from low conversions owing to a competing Ru‐catalyzed disproportionation of the oxidant. Gratifyingly, by switching to Oxone (2 KHSO5 ? KHSO4 ? K2SO4 triple salt) as stoichiometric oxidant, a more efficient and robust system was obtained that allowed for the oxidation of a wide range of aliphatic and benzylic secondary alcohols, giving the corresponding ketones in excellent yields. The mechanism for these reactions is believed to involve a high‐valent RuV–oxo species. We provide support for such an intermediate by means of mechanistic studies.  相似文献   

3.
Two methods for the oxidative rearrangement of tertiary allylic alcohols have been developed. Most of tertiary allylic alcohols studied were oxidized to their corresponding transposed carbonyl derivatives in excellent to fair yields by reaction with TEMPO in combination with PhIO and Bi(OTf)3 or copper (II) chloride in the presence or not of oxygen. Other primary oxidants of TEMPO such as PhI(OAc)2, mCPBA, and Oxone® were unsatisfactory giving the enone in modest to low yields.  相似文献   

4.
Fe(Cp)2BF4 is an efficient catalyst for the alcoholysis of aromatic, aliphatic, and cyclic epoxides giving excellent yields of the corresponding β-alkoxy alcohols under ambient conditions. The methanolysis of styrene oxide using Fe(Cp)2BF4 as a catalyst (5 mol %) gave excellent yield of 2-methoxy-2-phenylethanol with complete regio-selectivity. The ring opening of cyclic epoxides gave 77–97% yields of trans-β-methoxy alcohols, in 0.5–6 h. The use of 1,2-epoxyhexane and 1,2-epoxydodecane as substrates gave both regioisomers in excellent yields. The first order rate of reaction with respect to catalyst was observed for the kinetics of ring opening of 1,2-epoxyhexane with methanol.  相似文献   

5.
The reaction of allylic alcohols with carbon pronucleophiles in the presence of the Pd(PPh3)4/carboxylic acid combined catalytic system, under neat conditions (without an organic solvent or without water as the solvent) enabled the direct allylation of the pronucleophiles, giving the corresponding allylated products in high yields.  相似文献   

6.
Air-stable hypervalent organobismuth(III) tetrafluoroborate (C6H11N(CH2C6H4)2BiBF4) was synthesized and characterized by spectroscopic and X-ray crystallographic techniques. The compound shows good catalytic efficiency in the allylation reaction of different aldehydes with tetraallyltin in a medium of aqueous methanol, giving the corresponding homoallylic alcohols in excellent chemoselectivity and yields.  相似文献   

7.
N‐Methyl indole reacts with but‐2‐yn‐1‐ol in the presence of PtCl2 in MeOH giving indole derivatives having a substituted 3‐oxobutyl group at the 3‐position in good yield. Under the reaction conditions, various substituted indoles and substituted propargyl alcohols are successfully involved in the reaction giving the corresponding addition products in good to moderate yields. The catalytic reaction can be further extended to N‐phenyl pyrrole. In the present multi‐step reaction, PtCl2 likely plays dual roles: as the catalyst for the rearrangement of propargyl alcohols to the corresponding alkenyl ketones and as the catalyst for the addition of indoles to the alkenyl ketones. Experimental evidence is provided to support the proposed mechanism.  相似文献   

8.
Weihua Xue  Lifen Zhang 《中国化学》2012,30(8):1797-1800
The phosphoryl transfer reactions of diphenyl chlorophosphate with a wide range of alcohols were catalyzed by tris(pentafluorophenyl)boron [B(C6F5)3], giving the corresponding phosphate esters in excellent yields. This methodology has advantages over older ones because it employs the easily handled B(C6F5)3, avoids the side reaction, and has shorter reaction time.  相似文献   

9.
《Tetrahedron: Asymmetry》1998,9(22):3979-3984
A new chiral titanium reagent, derived from optically active trans-1,2-dicamphorsulfonamidocyclohexane 2a and Ti(OiPr)4, was found to promote the enantioselective addition of diethylzinc to various aldehydes giving rise to the corresponding alcohols in high yields with moderate to high selectivity.  相似文献   

10.
Summary Primary and secondary alcohols were oxidized to their corresponding aldehydes or ketones in good yields using Ru/Al2O3 as catalyst in the presence of acetone. The catalyst can be recovered by simple filtration and reused after washing with acetone.  相似文献   

11.
Various primary alcohols, particularly benzylic alcohols, could be converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq. NH3, followed by reaction with ∼30% aq H2O2. Similarly, various benzylic halides could be also converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq NH3, followed by reaction with ∼30% aq H2O2. The present reactions involve the metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into the corresponding aromatic amides, respectively.  相似文献   

12.
The reaction of 1-hydroxy-2-alkynylallylphosphonates, synthesized by the addition of the corresponding phosphites to 2-alkynylcinnamaldehydes, under AgOTf or Ph3PAuCl-AgSbF6 catalyzed cycloisomerization afforded 2-furylphosphonates in good to excellent yields. These cyclization reactions were compared with those of 2-alkynylallyl alcohols that led to multisubstituted furans.  相似文献   

13.
H. Firouazabadi  M. Adibi 《合成通讯》2013,43(13):2429-2441
Abstract

MePh3P+BH4 ? is able to reduce aldehydes and ketones to their corresponding alcohols in CH2Cl2. Aldehydes are reduced with high selectivity in the presence of ketones. α,β-Unsaturated carbonyl compounds undergo 1,2-reduction and produce their corresponding allylic alcohols in high yields. Carboxylic acid chlorides are also converted to their alcohols with high yields.  相似文献   

14.
The allylation of aldehydes and imines has efficiently been carried out by treatment with allyltributylstannane in the presence of a catalytic amount of ZrOCl2·8H2O in water to form the corresponding homoallylic alcohols and amines, respectively, in high yields.  相似文献   

15.
An effective, convenient, and mild coupling reaction of benzylic alcohols with terminal alkynes has been developed. As an effective Lewis acid, Cu(OTf)2-catalyzed arylmethylation of terminal alkynes with benzylic alcohols generated the corresponding products in BrCH2CH2Br with good yields in the absence of ligand, base, and additive.  相似文献   

16.
Zinc bromide (ZnBr2) under microwave irradiation efficiently catalyzed the Ferrier reaction of hindered phenols and alcohols to afford the corresponding α-2,3-unsaturated glucoside acetates in good yields and with good stereoselectivity. The reaction affords a facile access to new 2,3-dideoxyglucosides of important phenolic and alcoholic constituents of spices.  相似文献   

17.
An efficient method has been developed for the allylation of aldehydes with allytributylstannane in the presence of a catalytic amount of Mg(NTf2)2·xH2O at room temperature in water to afford the corresponding homoallylic alcohols in good yields.  相似文献   

18.
In the presence of a catalytic amount of Bi(OTf)3·4H2O and under microwave irradiation, neat mixtures of epoxides and amines afforded smoothly the corresponding 2-amino alcohols. A wide variety of aliphatic amines were reacted with cycloalkene oxide, styrene oxide, and stilbene oxide. The reaction proceeded rapidly and afforded the 2-amino alcohols in high up to quantitative yields. All products could be obtained without aqueous work-up by simple filtration.  相似文献   

19.
Studies on the photo-catalytic redox reaction of C1–C3 alcohols such as methanol, ethanol and 2-propanol were carried out in aqueous solution containing TiO2 photocatalyst (0.1% w/v) as suspension using 350 nm light. Other hydrocarbons such as ethane and ethene in the case of ethanol, and propene in the case of 2-propanol with low yields were produced along with the major photolytic products methane and carbon dioxide. The yields of methane and CO2 were found to be dependent on the light exposure time and ambient conditions. Methane yields were higher in 2-propanol and ethanol systems than in methanol system, showing their better hole-scavenging properties. In the aerated condition, methane was produced during photolysis of all alcohols in the presence of TiO2 and the yield was comparable to those observed in the corresponding CO2-saturated systems. The overall results reveal that the surface adsorbed, as well as in-situ-generated CO2 from photo-oxidation of alcohols are equally responsible for methane formation through photo-reduction in presence of TiO2. In the O2-saturated system, the methane yield was lower as compared to that in aerated system, in contrast to the CO2 yield. In N2O-and N2-purged systems, the yield of methane was observed to be low, inferring that the methane generation has not taken place through photodecomposition/photodissociation of alcohols. Again, photolysis of alcohols without TiO2 did not generate any methane.  相似文献   

20.
A simple and efficient method for the synthesis of alcohols from the corresponding carboxylic acids is described. Activation of carboxylic acid with 1-propanephosphonic acid cyclic anhydride (T3P) and subsequent reduction using NaBH4 yield the alcohol in excellent yields with good purity. Reduction of several alkyl/aryl carboxylic acids and Nα-protected amino acids/peptide acids as well as Nβ-protected amino acids was successfully carried out to obtain corresponding alcohols in good yields. All the products were fully characterized by 1H NMR and mass spectral analyses. The procedure is mild, simple and the isolation of the products is easy.  相似文献   

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