Bioactive Libraries

To address continuously growing interested to Drug Repurposing we designed and pre-plated Bioactive Library of 2 100 compounds including 646 FDA approved drugs and Phenotypic Screening Library to cover the widest therapeutic activities. The CLOUD library designed in collaboration with a group of researchers at CeMM specially for combinatorial studies showed interesting findings described in Nat. Chem. Biol. 2017, 13(7), 771–778.

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2 100 compounds


Library of well-known bioactive compounds with extensive target classes’ coverage and the broadest possible therapeutic areas applications – from CNS agents and anti-infectives to anticancer drugs and steroids

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646 compounds


A unique library of most diverse drugs

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5 760 compounds


Special diversity library created for Phenotypic Screens

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293 compounds


The comprehensive Drug Collection

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1 454 compounds


Versatile product to use in Drug Discovery

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PAINS Library



320 compounds


Special diverse selection of frequent hitters

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Related products & services

Additionally we provide broad functionalization of Drugs and relative actives with covalent warheads, biotin or/and dye-linking, PED-derivatization and other modifications. Versatile chemistry and the largest stock of valuable reagents enables Enamine to produce new functionalization of well-known drugs.

We combined most diverse approaches and possible structural modifications to achieve most complete representation of our Target identification tools.

Protein Degrader Toolbox

Protein Degradation Toolbox

Out-of-the-box tools for your research in PD

One of the most emerging therapeutics area focused on modulating the ubiquitin proteasome system is in dire need of new and reliable chemistry. Booming biological assays in this field of drug discovery require production of hundreds and thousands of new functional intermediates and bifunctional molecules. The time needed for production of new derivatives is crucial for any new project in this therapeutic area. We offer advanced synthetic chemistry support including custom library design and synthesis.

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To facilitate all further work on bifunctional molecules we constantly update our toolbox with newly synthesized intermediates and functionalized ligands. The actively developing area of Molecular Glues keeps us highly motivated to synthesize new Building Blocks and intermediates.

We offer distinct tools that you can mix-up to design molecules of your special interest. The following options are available for synthesis of new molecules or immediate delivery to your research site:

Cereblon ligands and functionalized intermediates
VHL ligands and ligands with linkers
Orthogonal Linkers
Molecular Glues
Functionalized Warhead Ligands
Active Degraders
Halo- & Photo- Capture Tags
SPLicing inhibitor sulfonAMides

World largest library of tangible building blocks

In 2007 Enamine Ltd and UORSY (Ukrorgsyntez Ltd) launched a joint project in order to establish a systematic chemically validated approach to synthesis of "in-stock-tomorrow" building blocks that consist of up to 21 heavy atoms and therefore can be used in medicinal chemistry and drug discovery. The average values for number of heavy atoms, MW and cLogP of the tangible building blocks are 18.3, 272 and 2.3, respectively. Full database (20 556 947 structures) and other relevant data including prices can be found at the library download page. The golden set of tangible building blocks (4 721 351 structures, containing up to 16 heavy atoms) have also been posted at Accelrys® Available Chemicals Directory. These databases are updated at least two times a year.

The main chemical classes of tangible building blocks are listed in the table below.

Type of Building Blocks Number of structures
Primary and Secondary Amines 4 484 000
Carboxylic Acids 1 009 000
Amino Acids 191 000
Alkylating and Arylating Agents 679 000
Sulfonyl Chlorides 26 000
Aldehydes and Ketones 317 000
Alkyl- and Arylhydrazines 43 000
Alcohols 852 000
Phenols 135 000
Thiols 27 000
Amidoximes and Amidines 118 000
Aryl bromides and Aryl iodides 743 000
Boronic acids 7 000
Alkyl- and Arylazides 7 600
Terminal acetylenes 34 000

Rigorously validated chemical procedures ensure high feasibility and cost effectiveness of tangible building blocks and fragments. About 8 500 building blocks were synthesized in 2009 with lead time of 4-6 weeks and feasibility of 80%.  Over 4 000 of these compounds were selected from the database of tangible building blocks and ordered by pharma and biotech companies worldwide at fixed prices ranging from 200 to 800 € per gram. Weekly progress reports on the synthesis of the ordered tangible building blocks and fragments are provided to the customers.

Screening collection

Screening Collection

We are proud to offer the world’s largest off-the-shelf collection of compounds for biological screening. Comprising of almost 2.9 M drug-like structures our collection has been proven to be an excellent source of starting points for the development of MedChem targets and analogues for hit expansion. Outstanding diversity of our collection ensures efficient coverage of the entire chemical space of commercially available screening compounds.

The compounds can be easily searched and purchased at or requested as a cherry-picked set. Our CADD team is at your service to compile pre-profiled or target-focused compound selections via filtering by phys-chem parameters, similarity and substructure searches, ligand-based and structure-based virtual screening, as well as pharmacophore modelling.


Through Enamine’s in-house validated parallel synthesis technology our screening collection is complemented with 150,000 new compounds yearly.

Thanks to the early focus of the company on development of its own inventory of MedChem relevant Building Blocks, the key emphasis of synthesis of new screening compounds is placed on the structural quality, uniqueness, diversity and molecular profile compliant with the modern trends in drug design.

Collection Structure

All Screening compounds in our stock are split into Premium, Advanced, HTS and Functional Collections in accordance with their key structural aspects and molecular properties:

HTS Collection: Comprehensive Drug-like compound set for high-throughput screening
  • Most extensive
  • Most diverse
  • Most affordable
Advanced Collection: Most recently synthesized Lead-like compounds
  • Ultimate novelty (<2-years)
  • Structures well-suited for lead discovery and targeted library design
  • Valuable pharmacophores present & Rigorous MedChem filters applied
Premium Collection: The compounds with most favorable phys-chem profile synthesized in our lead-oriented synthesis program
  • Outstanding structural quality and uniqueness
  • Excellent synthetic tractability
  • Prompt and efficient hit-follow-up guaranteed
Functional Collection: Versatile compounds with biological activity or specific structural features
  • Known bioactive compounds referred in open public domain
  • Covalent binders available
  • Compounds for PROTAC design
Liquid Stock:
  • Cherry-picking from 500 000 pre-dissolved compounds
  • Quickest delivery
  • Readily available as up to 10uL of 10mM DMSO solutions

Notably, according to the feedback from our most significant customers, the majority of sizable compound selections purchased for screening campaigns are compiled of at least 50% of Enamine compounds.

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Availability, Packaging, Quality Control

The compounds are available in multi-milligram amounts sufficient for fast re-supply (typically 100-300 mg). The samples are mainly stored as dry powders and can be delivered either dry, or as DMSO solutions of preferred concentration and volume, including “assay-ready”, in containers of your choice:

  • individual vials, 96-, 384- or 1536-well microplates
  • 2D-barcoded tube racks and Echo-qualified source plates

Mostly oily and sticky compounds are stored and shipped as DMSO solutions and are included to “Liquid Stock” to ensure smooth handling.

All Enamine compounds undergo rigorous quality control with LCMS and/or 1H NMR to meet the requirement of 90% purity. Higher quality standards (95%, 97%) are achievable via additional HPLC purification at extra charge. To ensure greater accuracy of the screening results we guarantee fast hit re-supply from the same batch in most cases. Additional purification and enhanced characterization can be offered as an additional service package.

Building Blocks Catalog

Building Blocks Catalog

Enamine designs, develops and synthesizes chemical reagents, scaffolds and intermediates widely known as building blocks. They are convenient for using in medicinal chemistry and synthesis of combinatorial compound libraries.


Our catalogue currently contains 1 152 295 building blocks including 284 000 compounds in stock, which can be delivered within 1-7 days from our global logistics centers in the USA and Europe, and via our official distributors in Asia and Oceania. To date, Enamine collection is the largest and most abundant single source of medchem building blocks in the world

Key Facts:

  • Most building blocks are available from stock in 1-5 g amounts.
  • At you can find up-to-date prices, availability, and lead times for most of the building blocks in stock and for synthesis.
  • All of our chemical building blocks undergo extensive quality control by NMR and LC-MS, and purity is guaranteed to be over 95%.
  • You can download MSDS and CoA for most of the building blocks here.

Below is a diagram showing stock composition by classes of building blocks:

Building Blocks by functions

MedChem Highlights

MADE Building Blocks

You can browse and purchase our building blocks at our online shop EnamineStore. There you will get up-to-date price, availability, and lead time information.

Each month our catalogue is enriched with over 1 500 new building blocks. You can be among the first to discover these innovative molecules by subscribing to our Catalogue Update Letters. Each of these monthly updates will bring you around 60 carefully selected, most interesting structures of building blocks that are available for immediate purchase from our stock.


Enamine offers world class service in chemical synthesis of a wide variety of organic compounds on the milligram to kilogram scale at competitive price.


We offer comprehensive support in developing your hit compounds. Naturally such programs are realised most efficiently when biological actives originate from our screening collection. However, even if the hit compounds are from the collections of other vendors lead identification and optimization projects can proceed most productively in our hands. Sometimes for this we only need to synthesize first examples of the given chemical series and validate synthesis route.


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