Regioselective Preparation of 1,2,3-Triazoles for Bioactive Studies Based on Marine Bioprospecting
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- Institutt for kjemi 
The azides 1d and 1c were prepared using literature procedures. The azides serve as starting materials in copper- and ruthenium-catalyzed 1,3-dipolar dipolar cycloadditions to N-protected alkynes 2a and 2b, to afford 1,4-disubstituted 1H-1,2,3-triazoles and 1,5-disubstituted 1H-1,2,3-triazoles, respectively. A recently published procedure for preparing 1c in one step from the aldehyde 5a was tested, but no product was obtained. The azide was synthesized by a more traditional approach, via the alchohol 6a. The novel 1,5-disubstituted 1H-1,2,3-triazole 3a was synthesized from azide 1a and N-protected alkyne 2a in a ruthenium-catalyzed 1,3-dipolar cycloaddition based on a literature procedure. 3a was obtained in a yield of 47%, after chromatographic purification. The novel 1,4-disubstituted 1H-1,2,3-triazoles 3b-f were prepared in copper-catalyzed 1,3-dipolar cycloaddtions between azides 1a, 1b, 1c and the N-protected alkynes 2a and 2b. The N-protected triazole 3b was deprotected to the corresponding amine 7b by hydrazinolysis. Work-up without significant loss of product proved challenging but the product was identified using 1D and 2D HNMR and CNMR experiments.