ophenone giving α-phenylthio-α-methylthio ketones. The methylthio transfer reaction between the ketone α-positions was reversible and at equilibrium, and the methylthio group was transferred in preference to the phenylthio group. The reaction of tertiary alkyl methylthiomethyl ketones proceeded in high yields; the reaction of diastereomeric 4-(tert-butyl)-2-phenylthiocyclohexanones gave an axial 2-methylthiolated
1] cycloaddition of propargylic carbamates and sulfur ylides was successfully developed. This strategy led to a series of chiral indolines with synthetically flexible alkyne groups in good yields and with high enantio- and diastereoselectivities (up to 99% yield, 98% ee, and >95:5 dr). A possible mechanism and stereoinduction mode with copper-allenylidenes were proposed as the possible dipolar intermediate
An Organocatalytic Regiospecific Synthesis of 1,5-Disubstituted 4-Thio-1,2,3-triazoles and 1,5-Disubstituted 1,2,3-Triazoles
作者:Dhevalapally B. Ramachary、Patoju M. Krishna、Jagjeet Gujral、G. Surendra Reddy
DOI:10.1002/chem.201503302
日期:2015.11.16
AbstractOrganocatalytic azide–ketone [3+2] cycloaddition (OrgAKC) of a variety of 1‐aryl‐2‐(arylthio)ethanones and 1‐alkyl‐2‐(alkylthio)ethanones with different aryl or alkyl azides is reported in dimethyl sulfoxide or solvent‐free under ambient conditions to furnish 1,5‐disubstituted 4‐thio‐1,2,3‐triazoles in a regiospecific manner, which are further converted into useful 1,5‐disubstituted 1,2,3‐triazoles by treatment with Raney Ni at 25 °C for 1–3 h. Notable features of the OrgAKC reaction include high rate and selectivity, solvent‐free conditions, easily available substrates and catalysts, a wide range of synthetic and medicinal applications, and excellent yields generating a vast library of triazoles.