Dong-Hong Li

Synthesis of functionalized tetrahydro-β-carboline derivatives by modified pictet-spengler reaction

Instead of iminium salt in Pictet-Spengler reaction, a series of indole-bearing secondary enamines were synthesized through one-carbon unit transfer reactions of a tetrahydrofolate coenzyme models with tryptamine, and applied to Pictet-Spengler reaction. Reaction of the secondary enamines in acid conditions produced a series of functionalized tetrahydro-β-carboline derivatives in good to excellent yields.

A Convenient Synthesis of 1‐Tosyl‐3, 4‐Dimethyl Imidazolium Salt and N,N,N′‐Trisubstituted Ethylendiamine Derivatives

Abstract 1‐Tosyl‐3,4‐dimethyl imidazolium iodide 3 was prepared by convenient cyclization, sulfonylation, and methylation from 4‐methyl‐2‐imidazoline, which was obtained by the reaction of ethyl formate with 1,2‐diaminopropane. Monofunctional carbon nucleophiles reacted with 3 to yield a series of N,N,N′‐trisubstituted ethylendiamine derivatives.

A convenient preparation of a series of 2-aryl-substituted imidazolidines through diamine transfer reaction

A series of 2-aryl-substituted imidazolidines were prepared through the simple diamine transfer reactions between 2-alkyl-substituted imidazolidines and aromatic aldehydes under the catalysis of n-butylamine.

Ethyl 2-acetyl-3-[2-(1H-indol-3-yl)­ethyl­amino]­propenoate

Secondary enamines have attracted a great deal of attention in recent years because of their range of applications (Duthaler, 2003; Stanovnik & Svete, 2004; Elassar & El-Khair, 2003). Moreover, functionalized secondary enamine derivatives may enable chemical and biological studies on these derivatives, which will be used in pharmaceutical research. We were therefore interested in the synthesis of secondary enamine derivatives during our investigation of tetrahydrofolate coenzyme models (Li et al., 2004). Tetrahydrofolate is involved in the biological transfer of a carbon unit at different oxidation levels (Blakley, 1969), which can transfer ÐC CÐ or CHÐ groups via mechanisms analogous to those operative in biochemical processes (Bieraugel et al., 1983; Pandit & Bieraugel, 1979).

1,2‐Di­methyl‐3‐(2‐nitro­phenyl)‐4,5‐di­hydro­imidazolium iodide

In the crystal structure of the title compound, C11H14N3O2+·I−, intermolecular C—H⋯O and C—H⋯I hydrogen bonds link the ions into a three-dimensional structure. The imidazolinium ring is planar within 0.0502 (2) A. The dihedral angle of the imidazolinium plane and the benzene ring plane is 78.45 (7)°.