Categories: Synthesis of N-Heterocycles >
Synthesis of 1,2,3-triazoles
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Name Reactions
Huisgen Azide-Alkyne 1,3-Dipolar Cycloaddition
Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC)
Ruthenium-Catalyzed Azide-Alkyne Cycloaddition (RuAAC)
Recent Literature
The synthesis of 1-monosubstituted aryl 1,2,3-triazoles was achieved in good
yields using calcium carbide as a source of acetylene. The copper-catalyzed
1,3-dipolar cycloaddition reactions were carried out without nitrogen protection
and in a MeCN-H2O mixture.
Y. Jiang, C. Kuang, Q. Yang, Synlett, 2009,
3163-3166.
Copper-Promoted One-Pot Sandmeyer-Type Reaction for the Synthesis of N-Aryltriazoles
M. Cui, R. Wang, Q. Yang, C. Kuang, J. Org. Chem., 2022, 87,
9654-9662.
A molecular iodine-mediated coupling cyclization reaction of N-tosylhydrazones
with sodium azide provides valuable 4-aryl-NH-1,2,3-triazoles via
sequential C-N and N-N bond formation. Mechanistic studies suggest that the
nitrogen atoms of the 1,2,3-triazoles are not entirely from sodium azide.
W.-M. Shu, X.-F. Zhang, X.-X. Zhang, M. Li, A.-J. Wang, A.-X. Wu, J. Org. Chem., 2019, 84,
14919-14925.
An iodine-mediated formal [2 + 2 + 1] cyclization of methyl ketones, p-toluenesulfonyl
hydrazines, and 1-aminopyridinium iodide provides 4-aryl-NH-1,2,3-triazoles
under metal- and azide-free conditions. This is achieved using p-toluenesulfonyl
hydrazines and 1-aminopyridinium iodide as azide surrogates.
C. Huang, X. Geng, P. Zhao, Y. Zhou, X.-X. Yu, L.-S. Wang, Y.-D. Wu, A.-X.
Wu, J. Org. Chem., 2021, 86,
13664-13672.
A (3+2) cycloaddition reaction between substituted vinyl sulfonyl fluorides and
ethyl diazoacetate or azides enables the rapid construction of pyrazole or
triazole cores via Michael addition and SO2 gas elimination.
K. Sandeep, A. S. Kumar, A. A. Qureshi, K. C. K. Swamy, Synthesis, 2022, 54,
4111-4119.
The use of polydentate N-donor chelating ligands enables a copper-catalyzed cycloaddition of hydrazoic acid with terminal alkynes
to provide 4-substituted-1H-1,2,3-triazoles in high yields at room temperature. Hydrazoic acid
was formed in situ from sodium azide under mildly acidic conditions in <6%
concentrations at which it is safe to handle.
D. Jankovič, M. Virant, M. Gazvoda, J. Org. Chem., 2022, 87,
4018-4028.
p-TsOH is a vital additive in the 1,3-dipolar cycloaddition of
nitroolefins and sodium azide. This p-TsOH-mediated cycloaddition enables
a rapid synthesis of valuable 4-aryl-NH-1,2,3-triazoles in high yields.
X.-J. Quan, Z.-H. Ren, Y.-Y. Wang, Z.-H. Guan, Org. Lett.,
2014,
16, 5728-5731.
A highly efficient and effective synthesis of N-unsubstituted
4-aryl-1,2,3-triazoles is promoted by Amberlyst-15. The ion exchange resin can
be recycled and reused up to eight times without loss of catalytic activity.
H. Zhang, D.-Z. Dong, Z.-L. Wang,
Synthesis, 2016, 48, 131-135.
A Pd-catalyzed synthesis of 1H-triazoles from alkenyl halides and
sodium azide represents a completely new reactivity pattern in the context of Pd
chemistry.
J. Barluenga, C. Valdés, G. Beltrán, M. Escribano, F. Aznar, Angew. Chem. Int. Ed., 2006, 45, 6893-6896.
J. Barluenga, C. Valdés, G. Beltrán, M. Escribano, F. Aznar, Angew. Chem. Int. Ed., 2006, 45, 6893-6896.
Treatment of 1,1-dibromoalkenes with n-butyllithium and reaction with
a sulfonyl azide gave 5-substituted 1-sulfonyl-1,2,3-triazoles. The use of
lithium base followed by transmetalation to zinc and reaction with aryl azides
allowed access to 1-aryl-1,2,3-triazoles. Finally, the use of EtMgBr as base and
reaction with an alkyl azide formed 1-alkyl-1,2,3-triazoles.
M. B. Williams, M. L. Martin, S. Wiedmann, Alistair Boyer, Synthesis, 2023,
55, 3862-3874.
A regioselective one-pot synthesis of 1,5-disubstituted 1,2,3-triazoles through
N/C-heterocyclization of allenylindium bromide across aryl azides is carried out
under mild conditions in aqueous medium and proceeds in good yields.
A. H. Banday, V. J. Hruby,
Synlett, 2014, 25, 1859-1862.
An efficient one-pot two-step synthesis of 1,4-disubstituted 1,2,3-triazoles
from α-ketoacetals and amines does not use metals,
azides, or oxidants, and tolerates a broad range of functional groups,
including heterocycles, esters, nitriles, and carbamates.
L. R. Zehnder, J. M. Hawkins, S. C. Sutton, Synlett, 2020,
31,
175-178.
A tandem catalysis protocol based on decarboxylative coupling of alkynoic acids
and 1,3-dipolar cycloaddition of azides avoids usage of gaseous or highly
volatile terminal alkynes, reduces handling of potentially unstable and
explosive azides to a minimum, and furnishes various functionalized
1,2,3-triazoles in excellent yields and a very good purity without the need for
additional purification.
A. Kolarovič, M. Schnürch, M. D. Mihovilovic, J. Org. Chem., 2011,
76, 2613-2618.
Self-assembly of copper sulfate and a poly(imidazole-acrylamide) amphiphile
provides a highly active, reusable, globular, solid-phase catalyst for click
chemistry. The insoluble amphiphilic polymeric imidazole Cu catalyst drove the
cycloaddition of various of alkynes and organic azides at very low catalyst
loadings and can be readily reused without loss of activity to give the
corresponding triazoles quantitatively.
Y. M. A. Yamada, S. M. Sarkar, Y. Uozumi, J. Am. Chem. Soc., 2012,
134, 9285-9286.
4-Aryl-1H-1,2,3-triazoles were synthesized from anti-3-aryl-2,3-dibromopropanoic
acids and sodium azide by using inexpensive copper(I) iodide as the catalyst in
the presence of cesium carbonate as base and DMSO as solvent.
Y. Jiang, C. Kuang, Q. Yang, Synthesis, 2010,
4256-4260.
4-Aryl-1H-1,2,3-triazoles were synthesized from anti-3-aryl-2,3-dibromopropanoic
acids and sodium azide by a one-pot method using N,N-dimethylformamide as
solvent in the presence of Pd2(dba)3 and Xantphos.
W. Zhang, C. Kuang, Q. Yang, Synthesis, 2010,
283-287.
1-Substituted-1,2,3-triazoles were conveniently synthesized from the
corresponding aromatic and aliphatic azides in the presence of acetylene gas
using mild, copper(I)-catalyzed ‘click chemistry'.
L.-Y. Wu, Y.-X. Xie, Z.-S. Chen, Y.-N. Niu, Y.-M. Liang, Synlett, 2009,
1453-1456.
A true Click catalytic system is based on commercially available [CuBr(PPh3)3].
This system is active at room temperature, with catalyst loadings of 0.5 mol %
or less, in the absence of any additive, and it does not require any
purification step to isolate pure triazoles.
S. Lal, S. Díez-González, J. Org. Chem., 2011,
76, 2367-2373.
Acid-Base Jointly Promoted Copper(I)-Catalyzed Azide-Alkyne Cycloaddition
C. Shao, X. Wang, Q. Zhang, S. Luo, J. Zhao, Y. Hu, J. Org. Chem., 2011,
76, 6832-6836.
A well-defined copper(I) isonitrile complex is an efficient, heterogeneous
catalyst for azide-alkyne cycloadditions and three-component
reactions of halides, sodium azide and alkynes to form 1,4-disubstituted
1,2,3-triazoles in high yields under mild conditions in water. The complex can
be recycled for at least five runs without significant loss of activity by
simple precipitation and filtration.
M. Liu, O. Reiser, Org. Lett., 2011,
13, 1102-1105.
Cycloadditions of copper(I) acetylides to azides and nitrile oxides provide
ready access to 1,4-disubstituted 1,2,3-triazoles and 3,4-disubstituted
isoxazoles, respectively. The process is highly reliable and exhibits an
unusually wide scope with respect to both components. Computational studies
revealed a nonconcerted mechanism involving unprecedented metallacycle
intermediates.
F. Himo, T. Lovell, R. Hilgraf, V. V. Rostovtsev, L. Noodleman, K. B. Sharpless,
V. V. Fokin, J. Am. Chem. Soc., 2005,
127, 210-216.
Triazole-based monophosphine ligands have been prepared via efficient
cycloadditions. Palladium complexes derived from these ligands are highly
active catalysts for Suzuki-Miyaura coupling and amination reactions of aryl
chlorides.
D. Liu, W. Gao, Q. Dai, X. Zhang, Org. Lett.,
2005, 7, 4907-4910.
A highly efficient method for the synthesis of multisubstituted 1,2,3-triazoles
via a direct Pd-catalyzed C-5 arylation has been developed.
S. Chuprakov, N. Chernyak, A. S. Dudnik, V. Gevorgyan, Org. Lett., 2007,
9, 2333-2336.
The use of nontoxic polyethylene glycol (PEG) as solvent and MesCO2H
as cocatalyst enabled user-friendly palladium(0)-catalyzed C-H bond
functionalizations under air in the absence of phosphine ligands. Direct
arylations of 1,2,3-triazoles gave substituted triazoles in good yields.
Recycling of the catalytic system led to a slight decrease of activity.
L. Ackermann, R. Vicente, Org. Lett., 2009,
11, 4922-4925.
Conditions for the palladium-catalyzed direct arylation of a wide range of
heterocycles with aryl bromides employ a stoichiometric ratio of both coupling
partners, as well as a substoichiometric quantity of pivalic acid, which results
in significantly faster reactions. An evaluation of the influence of the nature
of the aryl halide has also been carried out.
B. Liégault, D. Lapointe, L. Caron, A. Vlassova, K. Fagnou, J. Org. Chem., 2009,
74, 1826-1834.
An efficient I2/TBPB mediated oxidative formal [4 + 1] cycloaddition
of N-tosylhydrazones with anilines represents a simple, general, and
efficient approach for the construction of 1,2,3-triazoles under metal-free and
azide-free conditions.
Z.-J. Cai, X.-M. Lu, Y. Zi, C. Yang, L.-J. Shen, J. Li, S.-Y. Wang, S.-J. Ji, Org. Lett.,
2014,
16, 5108-5111.
A mild, zinc-mediated method for regioselective formation of 1,5-substituted
1,2,3-triazoles from a wide range of azides and alkynes works at room
temperature. Additionally, the triazole 4-position can be further functionalized
by reaction of the intermediate aryl-zinc with various electrophiles to
accommodate a diverse three-component coupling strategy.
C. D. Smith, M. F. Greaney, Org. Lett., 2013,
15, 4826-4829.
N3-Alkylation of 1-(pivaloyloxymethyl)-1,2,3-triazoles with alkyl triflates,
followed by a nucleophile-promoted N1-dealkylation of the resulting strongly
electrophilic intermediate triazolium salts, provides 1,5-disubstituted
1,2,3-triazoles.
Z. Monasterio, A. Irastorza, J. I. Miranda, J. M. Aizpurua, Org. Lett.,
2016, 18, 2515-2518.
The Cp2Ni/Xantphos catalytic system enables the synthesis of
1,5-disubstituted 1,2,3-triazoles under aqueous and ambient conditions.
This protocol is simple and scalable with a broad substrate scope including both
aliphatic and aromatic substrates.
W. G. Kim, M. E. Kang, J. B. Lee, M. H. Jeon, S. Lee, J. Lee, B. Choi, P. M. S.
D. Cal, S. Kang, J.-M. Kee, G. J. L. Bernardes , J.-U. Rohde, W. Choe, S. Y.
Hong, J. Am. Chem. Soc., 2017,
139, 12121-12124.
A Ce(OTf)3-catalyzed [3 + 2] cycloaddition of organic azides with
nitroolefins and subsequent elimination reaction selectively produces
1,5-disubstituted 1,2,3-triazoles in very good yields. Both benzyl and phenyl
azides react with a broad range of aryl nitroolefins containing a wide range of
functionalities.
Y.-C. Wang, Y.-Y. Xie, H.-E. Qu, H.-S. Wang, Y.-M. Pan, F.-P. Huang, J. Org. Chem., 2014,
79, 4463-4464.
1,5-Diarylsubstituted 1,2,3-triazoles are formed in high yield from aryl
azides and terminal alkynes in DMSO in the presence of a catalytic amount of
tetraalkylammonium hydroxide or t-BuOK for base-labile substrates. The
reaction is experimentally simple, does not require a transition-metal catalyst,
and is not sensitive to atmospheric oxygen and moisture.
S. W. Kwok, J. R. Fotsing, R. J. Fraser, V. O. Rodinov, V. V. Fokin, Org. Lett., 2010,
12, 4217-4219.
The use of t-BuOK in wet DMF as desilylating reagent in a cycloaddition
reaction of aromatic azides and trimethylsilyl alkynes generated
1,5-disubstituted 1,2,3-triazoles regioselectively in good yields at ambient
temperature.
L. Wu, X. Chen, M. Tang, X. Song, G. Chen, X. Song, Q. Lin, Synlett, 2012, 23,
1529-1533.
A Cu/Pd transmetalation relay catalysis enables a three-component click reaction
of azide, alkyne, and aryl halide to yield 1,4,5-trisubstituted 1,2,3-triazoles
in one step in high yields with complete regioselectivity. This reaction offers
an alternative to the well-established CuAAC click reactions only working on
terminal alkynes.
F. Wei, H. Li, C. Song, Y. Ma, L. Zhou, C.-H. Tung, Z. Xu, Org. Lett.,
2015,
17, 2860-2863.
In the presence of Cp*RuCl(PPh3)2 or Cp*RuCl(COD) as catalyst,
primary and secondary azides react with a broad range of terminal alkynes
containing a range of functionalities selectively producing 1,5-disubstituted
1,2,3-triazoles. Both complexes also promote the cycloaddition reactions of
organic azides with internal alkynes, providing access to fully-substituted
1,2,3-triazoles.
B. C. Boren, S. Narayan, L. K. Rasmussen, L. Zhang, H. Zhao, Z. Lin, G. Jia, V.
V. Fokin, J. Am. Chem. Soc., 2008,
130, 8923-8930.
In the presence of inexpensive copper (I) iodide as the catalyst, a series of
1,4-disubstituted 1,2,3-triazoles were synthesized in a one-pot process from
anti-3-aryl-2,3-dibromopropanoic acids and organic azides in dimethyl
sulfoxide.
X. Chen, Y. Yang, C. Kuang, Q. Yang, Synthesis, 2011,
2907-2912.
An efficient and convenient, copper-catalyzed decarboxylative cycloaddition of
propiolic acids, azides, and arylboronic acids provides fully substituted
1,2,3-triazoles from readily available starting materials. A possible mechanism
is proposed.
X.-X. Wang, Y. Xin, Y. Li, W.-J. Xia, B. Zhou, R.-R. Ye, Y.-M. Li, J. Org. Chem., 2020, 85, 3576-3586.
A copper(I)-catalyzed three-component reaction of amines, propargyl halides and
azides forms 1-substituted-1H-1,2,3-triazol-4-ylmethyl)-dialkylamines in
water. Synthetic advantages are high atom economy, low environmental impact,
atmospheric oxygen, wide substrate scope, mild reaction condition and good
yields.
Z.-Y. Yan, Y.-B. Zhao, M.-J. Fan, W.-M. Liu, Y.-M. Liang, Tetrahedron, 2005,
61, 9331-9337.
A method for the regiospecific synthesis of
1,4,5-trisubstituted-1,2,3-triazole catalyzed by copper(I) iodide was developed.
This is the first example of a regiospecific synthesis of
5-iodo-1,4-disubstituted-1,2,3-triazole, which can be further elaborated to a
range of 1,4,5-trisubstituted-1,2,3-triazole derivatives.
Y.-M. Wu, J. Deng, Y. L. Li, Q.-Y. Chen, Synthesis, 2005,
1314-1318.
Inexpensive copper catalysts enabled modular one-pot multicomponent syntheses
of fully decorated triazoles through a sustainable “click” reaction/direct
arylation sequence.
L. Ackermann, H. K. Potukuchi, D. Landsberg, R. Vicente, Org. Lett.,
2008,
10, 3081-3084.
L. Ackermann, H. K. Potukuchi, D. Landsberg, R. Vicente, Org. Lett.,
2008,
10, 3081-3084.
Microwave irradiation significantly enhances the rate of formation of
1,4-disubstituted 1,2,3-triazoles from alkynes and in situ generated azides.
Azides are derived from an efficient one-pot azidation of anilines with the
reagent combination t-BuONO and TMSN3.
A. D. Moorhouse, J. E. Moses, Synlett, 2008,
2089-2092.
A reliable and operationally simple one-pot reaction for a one-carbon
homologation of various aldehydes followed by Cu-catalyzed azide-alkyne click
chemistry gives 1,4-disubstituted 1,2,3-triazoles in good yields without the
need for isolation of the alkyne intermediates.
D. Luvino, C. Amalric, M. Smietana, J.-J. Vasseur, Synlett, 2007,
3037-3041.
1,2,3-Triazoles were prepared in good to modest yields by cycloaddition of
alkyl azides onto enol ethers under solventless conditions. The reaction can
access ring-fused triazoles that are unavailable by azide-alkyne cycloadditions
and is easily scalable. The 1,2,3-triazole products bear functionality that may
be readily derivatized.
D. R. Rogue, J. L. Neill, J. W. Antoon, E. P. Stevens, Synthesis, 2005, 2497-2502.
Copper(I)-Catalyzed Three-Component Click/Alkynylation: One-Pot Synthesis of
5-Alkynyl-1,2,3-triazoles
W. Wang, F. Wei, Y. Ma, C.-H. Tung, Z. Xu, Org. Lett.,
2016, 18, 4158-4161.
A copper(I)-mediated tandem three-component reaction using alkynes, azides,
allyl iodides, CuI and NaNH2 provides 5-allyl-1,2,3-triazoles smoothly at
room temperature in good yields. The products can be further
converted into 1,2,3-triazole-fused tricyclic scaffolds.
Y. Song, S. Lee, P. Dutta, J.-S. Ryu, Synthesis, 2020, 52,
744-754.
A copper-catalyzed three-component reaction of methyl ketones, organic azides,
and DMF as one-carbon (C1) donor provides 4-acyl-1,2,3-triazoles in good yields.
The transformation proceeds via an oxidative C-H/C-H cross-dehydrogenative
coupling followed by an oxidative 1,3-dipolar cycloaddition.
Y. Liu, G. Nie, Z. Zhou, L. Jia, Y. Chen, J. Org. Chem.,
2017, 82, 9198-9203.
The three-component reactions of enaminones, tosylhydrazine and primary amines
enabled a regioselective construction of 1,5-disubstituted 1,2,3-triazoles via
cascade dual C-N bond formation, N-N bond formation and an acyl migration-based
C-C bond formation. This metal- and azide-free method proceeds in the presence
of only molecular iodine.
J.-P. Wan, S. Cao, Y. Liu, J. Org. Chem.,
2015,
80, 9028-9033.
Domino reactions between NH-based secondary enaminones and tosyl azide enable
the synthesis of various N-substituted 1,2,3-triazoles via a key Regitz
diazo-transfer process by employing t-BuONa as the base promoter. The
reactions proceed efficiently at room temperature with good substrate tolerance.
J.-P. Wan, S. Cao, Y. Liu, Org. Lett.,
2016, 18, 6034-6037.
An electrochemical cycloaddition of secondary propargyl alcohol as C-3
synthon to sodium azide provide 4,5-disubstituted triazole derivatives at room
temperature in an undivided cell with a constant current using a pencil graphite
(C) anode and stainless-steel cathode in a MeCN solvent system.
M. Bandyopadhyay, S. Bhadra, S. Pathak, A. M. Menon, D. Chopra, S. Patra, J.
Escorihuela, S. De, D. Ganguly, S. Bhadra, M. K. Bera, J. Org. Chem., 2023, 88,
15772-15782.
A mild and metal-free multi-component reaction enables the synthesis of
4,5-disubstituted 1H-1,2,3-triazoles from phosphonium salts, aldehydes,
and sodium azide. An organocatalyzed coupling of the formyl group with the
phosphonium group provides an olefinic phosphonium salt as key intermediate,
that undergoes [3+2] cycloaddition with the azide.
G.-L. Wu, Q.-P. Wu, Synthesis, 2018, 50,
2768-2774.
TBAF-catalyzed [3 + 2] cycloadditions of 2-aryl-1-cyano- or
2-aryl-1-carbethoxy-1-nitroethenes with TMSN3 under solvent free
conditions allow the preparation of 4-aryl-5-cyano- or 4-aryl-5-carbethoxy-1H-1,2,3-triazoles under mild reaction conditions with good to excellent yields.
D. Amantini, F. Fringuelli, O. Piermatti, F. Pizzo, E. Zunino, L. Vaccaro, J. Org. Chem., 2005, 70, 6526-6529.
D. Amantini, F. Fringuelli, O. Piermatti, F. Pizzo, E. Zunino, L. Vaccaro, J. Org. Chem., 2005, 70, 6526-6529.
A copper-catalyzed [3 + 2] annulation of organic azides with
(2,2-difluorovinyl)zinc chloride-TMEDA provides 1-substituted 4-fluorotriazoles
in high yields via C-F bond cleavage. The difluorovinylzinc complex functions as
an easy-to-handle equivalent of the highly reactive and difficult to handle
fluoroacetylene (FC≡CH).
T. Fujita, M. Takeishi, J. Ichikawa, Org. Lett., 2020, 22, 9253-9257.
A directing-group-enabled regioselective Ir-catalyzed (3+2) cycloaddition of
azides and alkynes provides functionalized triazoles under mild conditions. The
triazene directing group can be replaced by diverse groups, including amino,
amide, halogen, and heterocycle substituents.
L. Zeng, Z. Lai, C. Zhang, H. Xie, S. Cui,
Org. Lett., 2020, 22, 2220-2224.
A general and regioselective metal-free cycloaddition of organic azides to a
hitherto underexplored bromovinylsulfonyl fluoride building block provides
4-fluorosulfonyl 1,2,3-triazoles. This reaction was extended to the synthesis of
various sulfonates, sulfonamides, and sulfonic acid derivatives of triazoles.
J. Thomas, V. V. Fokin, Org. Lett.,
2018, 20, 3749-3752.
A mechanochemical route enables a selective synthesis of 4-nitro-1,2,3-triazoles via
organocatalyzed oxidative [3 + 2] cycloaddition between β-nitrostyrenes and
organic azides. The reaction features a nontoxic catalyst, catalyst
recyclability, no rigorous solvent-extraction, no toxic byproducts, atmospheric
oxygen as oxidant, and scalability to gram-scale.
M. Vadivelu, A. A. Raheem, J. P. Raj, J. Elangovan, K. Karthikeyan, C. Praveen, J. Sun, Org. Lett.,
2022, 24, 2798-2803.
A copper-catalyzed [3 + 2] cycloaddition/oxidation reaction of nitro-olefins
with organic azides affords a broad range of 1,4(-NO2),5-trisubstituted
1,2,3-triazoles with high regioselectivities and in very good yields without
elimination of HNO2.
Y. Chen, G. Nie, Q. Zhang, S. Ma, H. Li, Q. Hu, Org. Lett.,
2015,
17, 1118-1121.
A ruthenium-catalyzed cycloaddition of N-Boc ynamides with azides gives
protected 5-amino-1,2,3-triazole-4-carboxylic acids, which are suitable for the
preparation of peptidomimetics. When aryl or alkyl azides are reacted with N-Boc-aminopropiolates
or arylynamides, the cycloaddition occurs with complete regiocontrol, while N-Boc-alkyl
ynamides yield a mixture of regioisomers.
S. Ferrini, J. Z. Chandanshive, S. Lena, M. C. Franchini, G. Giannini, A. Tafi,
M. Taddei, J. Org. Chem.,
2015,
80, 2562-2572.
A three-component assembly of α-CF3 carbonyls, NaN3,
and amines provides a variety of 5-amino NH-1,2,3-triazoles under
transition-metal-free and open-air conditions. The method provides a general and
operationally simple route to functionalized biologically important molecules.
The NH-1,2,3-triazoles can be smoothly converted to N-2 alkylated
1,2,3-triazole products.
L. Lv, G. Gao, Y. Luo, K. Mao, Z. Li, J. Org. Chem., 2021, 86,
17197-17212.
Copper catalyzes a rapid assembly of 5-carboxyl-4-perfluoroalkyl-triazoles
from N-tosylhydrazides and perfluoroalkyl acetoacetates. The approach
exhibits high functional group tolerance and can be executed on a multigram
scale.
R. Panish, T. Thieu, J. Balsells, Org. Lett., 2021, 23,
5937-5941.