An efficient and improved procedure for preparation of triflyl azide and application in catalytic diazotransfer reaction

A New Robust and Versatile Tetradentate Linker for Amides To be Cleaved under Mild Conditions by Unusual Complexation of the Amide Nitrogen to Cu++

“…This was followed by cleavage of the Fmoc group with 20 % piperidine in DMF. A diazo transfer with the use of triflic azide [14] and a catalytic amount of CuSO 4 ·5H 2 O led to quantitative azide formation, which was proven by a negative Kaiser test. For this diazo transfer a small amount of MeOH was added to the reaction mixture to enhance the solubility of CuSO 4 , although this might have caused a minute amount of premature cleavage by methanolysis.…”

“…to solid support 26 and after subsequent washing steps, solid support 34 was suspended in DMF/piperidine (8:2, 2 ϫ 4 mL, 5 min) to yield the Fmoc-deprotected solid support. For the following diazo transfer, a freshly prepared solution of triflic azide [14] in pyridine (0.7 , 4.2 mL, 2.94 mmol, 18 equiv. ), CuSO 4 ·5H 2 O (4.2 mg, 17 µmol, 10 mol-%), and MeOH (0.5 mL) were added to the solid support.…”

Synthesis and Cytotoxicity of Ring C‐Functionalized Derivatives of the Marine Natural Product (–)‐Dibromophakellstatin

“…The conversion of amine 29 to azide 30 was accomplished by reaction with freshly prepared triflyl azide with the adaptation of a copper-catalyzed diazo transfer reaction. [16] Azide 30 was purified by filtration through a pad of silica gel [CHCl 3 /MeOH (9:1) + 1 % aqueous ammonia] but was unstable and used immediately in the subsequent click reaction. As an alternative coupling partner for the terminal alkyne 23, aminoazide 32 was prepared starting from hexaethylene glycol (31) in three steps by double tosylation, conversion to the diazide [17] and mono-Staudinger reduction (Scheme 5b).…”

Synthesis of a tetrasaccharide substrate of heparanase

“…The 4-OH free GlcN derivatives 5 and 8 were both prepared from D-glucosamine hydrochloride in five steps (16% and 17% yields, respectively). Thus, 2-azido-2-deoxy-D-glucopyranose 9, resulting from the diazotransfer reaction of D-glucosamine hydrochloride with triflyl azide, 10 was treated with p-MeOPhCH(OMe) 2 in the presence of p-TsOH in DMF to give 1,3-diol 10 (68% from GlcN). Diol 10 was subjected to selective protection with TBSCl in the presence of imidazole at low temperature (À15°C, CH 2 Cl 2 ) followed with BnBr and NaH in THF, providing the 3-OBn-1-b-O-TBS ether 11 regio-and stereoselectively in a good 69% yield.…”