I am pleased to report that Andrew Lang and I have published the first edition of the Reaction Attempts book. It currently contains most of the Ugi reactions from the UsefulChem project and is associated with an April 27, 2010 snapshot archive of the entire UsefulChem project, including NMR spectra, spreadsheets, images and the entire lab notebook from Wikispaces.
We are hoping to include reaction attempts from other groups in future editions. More details can be found in the preface, reproduced below:
Reaction Attempts First Edition
Data Source: the UsefulChem project
Open Notebook Science (ONS) refers to the practice of making the full contents of a laboratory notebook and all associated raw data files available in near real time. This represents an opportunity for everyone to benefit from work in progress in an open research group. However, in order to make use of the information, it must be easily discoverable. A simple strategy to increase discoverability is redundancy over multiple communication platforms.
In another project - the Open Notebook Science Solubility Challenge - we published non-aqueous solubility data in the form of physical and downloadable (PDF) books. Although it is possible to search the solubility database using web query interfaces, exploration of a Google Spreadsheet, an XML feed, etc., having a physical copy in the laboratory has proved to be very convenient in several instances. A similar format for reactions will also be useful.
The UsefulChem Project
UsefulChem started in 2005 as an organic chemistry Open Notebook Science project with a main goal of discovering new anti-malarial agents that can be prepared by simple and cheap syntheses. Most of the reactions on UsefuChem are Ugi reactions, which involve the mixing of an amine, aldehyde, carboxylic acid and isonitrile in a solvent at room temperature generally for a few hours to days. The multicomponent design of the Ugi reaction and the simple reaction conditions make it ideal for exploring large virtual libraries and selecting compounds of interest to make.
Isolation of the Ugi products can be immensely simpler, cheaper and readily scalable if they precipitate in pure form from the reaction mixture. To this end, much of the research in the UsefulChem project focuses on reaction conditions that lead to this outcome. This is in fact the origin of the ONS Solubility Challenge discussed above.
The Reaction Attempts Database
In order to look for patterns in the reaction conditions which led to Ugi product precipitation, the CombiUgiResults Google Spreadsheet was set up. Reactions indexed there can be sorted by precipitation outcome, solvent, reactant, concentration, etc. and links to the laboratory notebook pages can be followed for full details. However, this sheet is designed specifically for Ugi reactions and contains columns specifically for the aldehyde, amine, carboxylic acid and isonitrile.
In order to enable the tracking of other types of reactions, the information in the CombiUgiResults sheet was reformatted into two other sheets: ReactionAttempts (containing reagents and reactants) and RXIDsReactionAttempts (containing reaction conditions and results, such as solvent, concentration of limiting reactant, appearance of a precipitate, yield, etc.). The two sheets are connected via the use of a common ReactionID. This format permits the representation of any type of reaction, with an unlimited number of reactants and products.
By definition, any Open Notebook Science project in a work in progress. The listing of a reaction in this database only means that the researcher attempted or is in the process of attempting it. Whatever the situation, a link to the laboratory notebook page is provided, where the most recent information is available. The philosophy used here is that partial information is always better than no information at all. Thus a researcher investigating the prior use a particular reactant in a Ugi reaction might find the report that a precipitate was obtained in methanol helpful for designing their own reactions, even if the characterization of the precipitate is still pending. At the very least, knowing that a certain researcher has at least attempted a similar reaction is enough information for initiating a discussion, which may lead to valuable insights.
Reaction Attempts on Chemspider
Although SMILES are provided in the spreadsheets, the primary key to identify compounds is the ChemSpider ID (CSID). This allows us to render molecule images in the book automatically. In the case of the ONS Solubility Challenge book, use of the CSID enables a convenient way to calculate various descriptors for displaying values in the book.
In addition, the compounds in the Reaction Attempts database are indexed on ChemSpider as two Data Sources: ReactantsAttemptedReactions and ProductsAttemptedReactions. In this way a substructure search for either reactants or products will identify indexed molecules. Clicking on the Syntheses tab in the ChemSpider record for a selected molecule will then reveal a list of hyperlinks to the relevant laboratory notebook pages.
Organization of the Book
In keeping with the layout of the ONS Solubility Challenge Book, the reactants are listed in alphabetical order. Each entry displays the list of reactions where the reactant was used. This includes a scheme with all reactants and product as well as key metadata: the researcher, reaction type, solvent, limiting reactant concentration, observation of a precipitate, comments and a reference (links to the laboratory notebook page).
In this edition, only Ugi reactions are included. The reaction schemes are laid out in the following order: carboxylic acid, amine, aldehyde and isonitrile. This should allow for easy comparison between schemes within a given record. Reactions where the Ugi product was isolated and characterized are marked with a green check and the percent yield is noted. Since the Ugi products do not have simple common names, they are not included as separate entries. However, all reactions where the synthesis of a specific Ugi product was attempted can be found by looking up the entries for any of the four reactants.
Although this compilation is not exhaustive, it does cover the vast majority of reactions in the UsefulChem project to date. Future editions will include other reactions from UsefulChem and other sources.
This edition is linked to the UsefulChem data archive (ZIP), (DVD) and interactive hosted archive format, ReactionAttempts (XLS) and RXIDsReactionAttempts(XLS) taken on 2010-04-27.
1. Open Notebook Science Wikipedia Entry http://en.wikipedia.org/wiki/Open_Notebook_Science
2. Open Notebook Science Solubility Challenge Wiki http://onschallenge.wikispaces.com
3. Bradley, J.-C. First Edition of ONS Solubility Challenge Book UsefulChem Blog (2009)
4. Open Notebook Science Solubility Challenge List of Experiments page http://onschallenge.wikispaces.com/list+of+experiments
5. UsefulChem Wiki http://usefulchem.wikispaces.com
6. Ugi Reaction Wikipedia Entry http://en.wikipedia.org/wiki/Ugi_reaction
7. Dömling, A., & Ugi, I. (2000). Multicomponent Reactions with Isocyanides. Angewandte Chemie International English Edition, 39(18), 3168-3210. http://www3.interscience.wiley.com/journal/73500473/abstract.
8. UsefulChem List of Experiments http://usefulchem.wikispaces.com/All+Reactions
9. Bradley, J.-C. Open Notebook Science Challenge UsefulChem Blog (2008)
10. CombiUgiResults Google Spreadsheet http://spreadsheets.google.com/ccc?key=plwwufp30hfpUERhse9y5Kw
11. ReactionAttempts Google Spreadsheet
12. RXIDsReactionAttempts Google Spreadsheet
13. Bradley, J.-C. Reaction Attempts on ChemSpider UsefulChem Blog (2010)
14. SMILES Wikipedia Entry http://en.wikipedia.org/wiki/Simplified_molecular_input_line_entry_specification
15. ChemSpider Web Site http://www.chemspider.com/
16. UC archive Drexel server (ZIP) http://showme.physics.drexel.edu/usefulchem/archives/usefulchem2010-04-27.zip
17. UC archive on lulu.com (DVD) http://www.lulu.com/product/dvd/usefulchem-archive/10791847
18. UC interactive hosted format http://showme.physics.drexel.edu/usefulchem/archives/usefulchem2010-04-27/All%20Reactions.html
19. Bradley, J.-C.; Lang, A.. Reaction Attempts Reactants and Products. UsefulChem. 2010-04-27.