Triflic Acid Catalyzed Reductive Coupling Reactions of Carbonyl Compounds with O-, S-, and N-Nucleophiles
作者:Beate A. Gellert、Nils Kahlcke、Markus Feurer、Stefanie Roth
DOI:10.1002/chem.201101819
日期:2011.10.17
Highly efficient metal‐free reductivecoupling reactions of aldehydes and ketones with a range of nucleophiles in the presence of triflic acid (1–5 mol %) as the catalyst are presented. The reactions can be performed at ambient temperature without exclusion of moisture or air. A range of symmetrical and unsymmetrical ethers were obtained by this method in high yields and short reaction times. For the
Secondary benzylic alcohols are coupled in the presence of zirconiumtetrachloride to afford the corresponding symmetrical ethers in good yields. Unsymmetric ethers are obtained with good selectivity by condensation of two different secondary benzylic alcohols under the action of the same catalyst.
The interaction of D,L-1-(4-nitrophenyl)ethanol with SOCl2 and P4O10 has been studied. In the reaction of D,L-1-(4-nitrophenyl)ethanol with SOCl2 a mixture of 1-(4-nitrophenyl)-1-chloroethane, 1,1'-bis-(4-nitrophenyl)diethyl ether, and 4-nitrostyrene (yield 21%) has been formed. The direction of reaction of D,L-1-(4-nitrophenyl)ethanol with P4O10 in toluene has been affected significantly by the order of reagents addition and the solution concentration. 4-Nitrostyrene has been obtained in the only case: the addition of P4O10 to a diluted solution of D,L-1-(4-nitrophenyl)ethanol and subsequent refluxing. Also the procedure of 4-nitrostyrene preparation via the cleavage of 2-(4-nitrophenyl)ethyl nitrate with alkoxy anion in the alcoholic solution has been upgraded.
Über die Darstellung einiger p-substituierter Styrolderivate