We have reported that AmberliteIRA900F (Amb-F) is an efficient metal-free catalyst for the activation of Si–N and Si–O bonds and a mild base in a variety of organictransformationsundersolvent-freeconditions, such as the addition of TMSN3 to (E)-2-aryl-1-cyano-1-nitroethenes, nitriles, α,β-unsaturated acids and their esters, and the addition of dimethylsilylketene acetal and ethyl nitroacetate
found to catalyse Knoevenagelcondensation between aromatic aldehyde and cyano compound with active methylene hydrogens and this has led to a successful route for the onepotsynthesis of 4,5-disubstituted 1,2,3-(NH)-triazoles from aldehydes through Knoevenagel-[3+2]cycloaddition-elimination sequence. In the formation of 5-aryl-2H-1,2,3-triazole-4-carbonitrile derivatives, the reaction has been found
已发现叠氮化钠催化芳香醛和氰基化合物与活性亚甲基氢之间的Knoevenagel缩合反应,这已导致一锅法合成一锅法合成4,5-二取代1,2,3-(NH)-三唑的成功途径。通过Knoevenagel- [3 + 2]环加成-消除序列形成醛。在形成5-芳基-2 H -1,2,3-三唑-4-腈的衍生物中,发现该反应在水中有效地发生。
[3+2] Cycloaddition Reactions in the Solid-Phase Synthesis of 1,2,3-Triazoles
作者:Yongnian Gao、Yulin Lam
DOI:10.1021/ol0611494
日期:2006.7.1
[Structure: see text] An efficient and regioselective procedure for the synthesis of 1,2,3-triazoles via a [3+2] cycloaddition of polymer-bound vinyl sulfone and sodium azide is described. Microwave irradiation provided significant rate enhancement in all steps of the three-step protocol. A representative set of 23 compounds was prepared.
An expedient synthesis of N-unsubstituted 1,2,3-triazole-4-carboxylates has been demonstrated through [3 + 2] cycloaddition of sodium azide with α-haloacrylates. The process is highly reliable and exhibits an unusually wide scope with respect to α-fluoro-, α-chloro-, α-bromo-, and α-iodoacrylates. The potential of selected 1,2,3-triazole-4-carboxylates in the preparation of 1,5-dihydro-4H-[1,2,3]-triazolo-[4,5-c]-quinolin-4-one has also been illustrated.