References & Further Reading
Key publications, reviews, and resources for click chemistry research. The references below span the foundational definitions of click chemistry through the latest developments in bioorthogonal reactions and clinical translation.
Foundational Papers
[1] Kolb, H. C.; Finn, M. G.; Sharpless, K. B. "Click Chemistry: Diverse Chemical Function from a Few Good Reactions." Angew. Chem. Int. Ed. 2001, 40, 2004–2021.
The defining manifesto of click chemistry, establishing the criteria of high yield, wide scope, simple conditions, and benign solvents that characterize a "click" reaction.
[2] Rostovtsev, V. V.; Green, L. G.; Fokin, V. V.; Sharpless, K. B. “A Stepwise Huisgen Cycloaddition Process: Copper(I)-Catalyzed Regioselective ‘Ligation’ of Azides and Terminal Alkynes.” Angew. Chem. Int. Ed. 2002, 41, 2596–2599.
The Sharpless group's independent report of the copper-catalyzed azide-alkyne cycloaddition (CuAAC), demonstrating exclusive 1,4-regioselectivity and room-temperature conditions.
[3] Tornøe, C. W.; Christensen, C.; Meldal, M. “Peptidotriazoles on Solid Phase: [1,2,3]-Triazoles by Regiospecific Copper(I)-Catalyzed 1,3-Dipolar Cycloadditions of Terminal Alkynes to Azides.” J. Org. Chem. 2002, 67, 3057–3064.
Meldal's simultaneous and independent discovery of CuAAC, applied to solid-phase peptide synthesis to produce triazole-linked peptidomimetics.
[4] Agard, N. J.; Prescher, J. A.; Bertozzi, C. R. “A Strain-Promoted [3 + 2] Azide−Alkyne Cycloaddition for Covalent Modification of Biomolecules.” J. Am. Chem. Soc. 2004, 126, 15046–15047.
The landmark report introducing strain-promoted azide-alkyne cycloaddition (SPAAC) using cyclooctynes, eliminating the need for copper catalyst and enabling bioorthogonal labeling in living systems.
Bioorthogonal Chemistry
[5] Sletten, E. M.; Bertozzi, C. R. “Bioorthogonal Chemistry: Fishing for Selectivity in a Sea of Functionality.” Angew. Chem. Int. Ed. 2009, 48, 6974–6998.
A comprehensive review defining the concept of bioorthogonality and cataloguing the reaction classes that proceed cleanly in biological milieux without interfering with native biochemistry.
[6] Prescher, J. A.; Bertozzi, C. R. “Chemistry in Living Systems.” Nat. Chem. Biol. 2005, 1, 13–21.
An early perspective on applying selective chemical reactions to probe and manipulate biological processes in living cells and organisms, laying the conceptual groundwork for bioorthogonal chemistry.
IEDDA & Tetrazine Chemistry
[7] Blackman, M. L.; Royzen, M.; Fox, J. M. “Tetrazine Ligation: Fast Bioconjugation Based on Inverse-Electron-Demand Diels−Alder Reactivity.” J. Am. Chem. Soc. 2008, 130, 13518–13519.
The first report of tetrazine/trans-cyclooctene (TCO) ligation for bioconjugation, achieving second-order rate constants orders of magnitude faster than CuAAC or SPAAC.
[8] Devaraj, N. K.; Weissleder, R.; Hilderbrand, S. A. “Tetrazine-Based Cycloadditions: Application to Pretargeted Live Cell Imaging.” Bioconjugate Chem. 2008, 19, 2297–2299.
Demonstrates the use of tetrazine/TCO chemistry for pre-targeted imaging of live cells, highlighting the reaction's speed and selectivity under physiological conditions.
Reaction Kinetics & Suitability
[9] Liu, H.; Audrain, R.; et al. “Click Chemistry: Reaction Rates and Their Suitability for Biomedical Applications.” Bioconjugate Chem. 2024, 35, 575–595.
A recent systematic comparison of rate constants across click reaction families (CuAAC, SPAAC, IEDDA, Staudinger, thiol-ene) with guidance on matching reaction speed to biomedical application requirements.
Review Articles & Textbooks
[10] Hein, J. E.; Fokin, V. V. “Copper-Catalyzed Azide–Alkyne Click Chemistry for Bioconjugation.” Chem. Soc. Rev. 2010, 39, 1302–1315.
A detailed review of CuAAC methodology, mechanism, ligand design, and applications to biomolecule labeling and conjugation.
[11] Thirumurugan, P.; Matosiuk, D.; Jozwiak, K. “Click Chemistry for Drug Development and Diverse Chemical–Biology Applications.” Chem. Rev. 2013, 113, 4905–4979.
A broad survey covering click chemistry applications in drug discovery, molecular imaging, polymer science, and nanotechnology, with emphasis on pharmacologically relevant examples.
[12] "Click Chemistry in Biology" — Chapter in Comprehensive Organic Chemistry Experiments for the Laboratory Classroom, RSC Publishing.
A practical laboratory guide with step-by-step experimental protocols for performing click reactions on biological substrates, suitable for graduate-level teaching and research.
Online Resources
Nobel Prize 2022 — Official Summary
The Nobel Foundation's official summary of click chemistry and bioorthogonal chemistry, including laureate biographies and scientific background documents.
AcademicPubChem — NCBI Compound Database
Open-access chemical database from the U.S. National Center for Biotechnology Information. Search for click reagents by structure, molecular formula, or synonym.
Open Access DatabaseChemSpider — Royal Society of Chemistry
Free chemical structure database aggregating data from hundreds of sources. Provides properties, spectra, and literature references for click chemistry reagents and products.
Open Access DatabaseIUPAC Gold Book — Compendium of Chemical Terminology
The authoritative IUPAC reference for chemical terminology definitions, including cycloaddition, bioorthogonal, and related terms used throughout this knowledge base.
Standards & TerminologyNobel Prize 2022
The Nobel Prize in Chemistry 2022 was awarded jointly to Carolyn R. Bertozzi, Morten Meldal, and K. Barry Sharpless "for the development of click chemistry and bioorthogonal chemistry."
Sharpless and Meldal independently discovered the copper-catalyzed azide-alkyne cycloaddition (CuAAC), the crown jewel of click chemistry. Bertozzi developed bioorthogonal chemistry, extending click reactions to living organisms without disrupting normal cellular processes — most notably through strain-promoted azide-alkyne cycloaddition (SPAAC) and the application of click chemistry to map glycans on cell surfaces.