Categories: Synthesis of N-Heterocycles >
Synthesis of tetrazoles
Recent Literature
Treatment of organic nitriles with NaN3 in the presence of iodine or
silica-supported sodium hydrogen sulfate as a heterogeneous catalyst enables an
advantageous synthesis of 5-substituted 1H-tetrazoles.
B. Das, C. R. Reddy, D. N. Kumar, M. Krishnaiah, R. Narender, Synlett, 2010,
391-394.
5-Substituted tetrazoles were prepared in very good yields and short reaction
times by treatment of nitriles with sodium azide and triethylammonium chloride
in nitrobenzene in a microwave reactor. Even sterically hindered tetrazoles, as
well as those deactivated by electron-donating groups, can be prepared.
J. Roh, T. V. Artamonova, K. Vávrová, G. I. Koldobskii, A. Hrabálek, Synthesis, 2009,
2175-2178.
An organocatalyst, 5-azido-1-methyl-3,4-dihydro-2H-pyrrolium azide,
generated in situ from N-methyl-2-pyrrolidone (NMP), sodium azide, and
trimethylsilyl chloride, enables the formation of tetrazoles by cycloaddition of
sodium azide with organic nitriles under neutral conditions and microwave
heating. The organocatalyst accelerates the azide-nitrile coupling by activating
the nitrile substrate.
D. Cantillo, B. Gutmann, C. O. Kappe, J. Am. Chem. Soc., 2011,
133, 4465-4475.
A series of 1-substituted 1H-1,2,3,4-tetrazole compounds have been
synthesized in good yields from amines, triethyl orthoformate, and sodium
azide through the catalyzed reaction with Yb(OTf)3.
W.-K. Su, Z. Hong, W.-G. Shan, X.-X. Zhang, Eur. J. Org. Chem., 2006,
2723-2726.
A series of primary alcohols and aldehydes were treated with iodine in ammonia
water under microwave irradiation to give the intermediate nitriles, which
without isolation underwent [2 + 3] cycloadditions with dicyandiamide and sodium
azide to afford the corresponding triazines and tetrazoles in high yields.
J.-J. Shie, J.-M. Fang, J. Org. Chem., 2007,
72, 3141-3144.
J.-J. Shie, J.-M. Fang, J. Org. Chem., 2007,
72, 3141-3144.
Cascade reactions starting from isocyanides allow a straightforward synthesis of
five-membered ring heterocycles. Addition of sodium azide on isocyanide
dibromides followed by electrocyclization and a Suzuki coupling affords
tetrazoles scaffolds, whereas addition of tetrazoles on isocyanide dibromides
followed by Huisgen rearrangement and a Suzuki coupling gives triazoles
scaffolds.
L. El Kaim, L. Grimaud, P. Patil, Org. Lett., 2011,
13, 1261-1263.
A general method for the synthesis of 1,5-disubstituted tetrazoles from
imidoylbenzotriazoles involves mild reaction conditions and short reaction times.
A. R. Katritzky, C. Cai, N. K. Meher, Synthesis, 2007,
1204-1208.
The reaction of cyanogen azide and primary amines generates imidoyl azides as
intermediates in acetonitrile/water. After cyclization, these intermediates gave
1-substituted aminotetrazoles in good yield.
Y.-H. Joo, J. M. Shreeve, Org. Lett.,
2008,
10, 4665-4667.
A versatile and highly efficient Zn(OTf)2-catalyzed one-pot
reaction of alkenes, NBS, nitriles, and TMSN3 gives various 1,5-disubstituted
tetrazoles containing an additional α-bromo functionality of the N1-alkyl
substituent.
S. Hajra, D. Sinha, M. Bhowmick, J. Org. Chem., 2007,
72, 1852-1855.
The reaction of 2-halopyridines with trimethylsilyl azide in the presence of
tetrabutylammonium fluoride hydrate gives tetrazolo[1,5-a]pyridines.
8-bromotetrazolo[1,5-a]pyridine is further transformed into a variety of
novel tetrazolo[1,5-a]pyridine derivatives.
J. K. Laha, G. D. Cuny, Synthesis, 2008,
4002-4006.
Pyridine N-oxides were converted to tetrazolo[1,5-a]pyridines in good yield in the presence of sulfonyl or phosphoryl azides and pyridine by
heating in the absence of solvent. Diphenyl phosphorazidate (DPPA) was the
most convenient reagent.
J. M. Keith, J. Org. Chem., 2006,
71, 9540-9543.
