Organic Chemistry Reagents Table

Reagent tables are useful until they mislead you

I used to print out full reagent tables and tape them above my bench. The standard ones cover around two hundred entries — reducing agents, oxidants, protecting group reagents, catalysts, bases, nucleophiles, and so on. They look clean on paper. In practice, most of what you actually need boils down to maybe thirty reagents that do the heavy lifting in a typical synthesis sequence. When I first started running reactions, I kept getting tripped up by entries that listed a reagent as universally effective when the conditions were actually very specific. Take sodium borohydride for example. Everyone knows it reduces aldehydes and ketones, but that does not mean it stops there. It will reduce acid chlorides too, and under certain conditions it even touches esters if you push it hard enough. A basic table entry saying "selective for aldehydes and ketones" sounds reassuring until you are trying to deprotect a protected sugar and realize your NaBH4 just chewed through the ester linkage you thought was fine.

Building Your Own Organic Chemistry Reagents Table

Here is how I actually approach this. Start with a spreadsheet or a simple database. Three columns minimum: reagent name, primary function, and key limitations. Add columns for solvent compatibility, temperature range, and typical reaction time. That last column matters more than most people realize because a reagent listed with a generic "room temperature" note can be completely useless at ambient conditions for a sluggish transformation. I keep a column for workup notes too. Some reagents require quenching with aqueous sodium bicarbonate, others need careful acidic workup, and a few like DIBAL-H demand cryogenic handling and immediate hydrolysis. Forgetting the workup detail on a printed table has cost me at least one good batch before. The format that works for me is tab-separated values. You can open it in anything — LibreOffice Calc, Google Sheets, even Excel if you are still stuck with that. A CSV file transfers between lab computers without format corruption, which is more important than it sounds when you are swapping machines between buildings and one of them runs an older Office version. I organize reagents by class rather than alphabetically. Grouping by reducing agents, oxidants, coupling reagents, acid catalysts, and so on means you do not have to hunt through two hundred rows to find what you need. When you are planning a route and thinking about oxidation state changes, having everything in that class visible at once saves time. I also include a column for the byproduct profile. Knowing that a Mitsunobu reaction generates triphenylphosphine oxide as a stoichiometric waste product changes how you think about purification compared to a catalytic method that leaves minimal residue.

For actual data sources, the main references are Clayden, Greeves, and Warren for general transformations, paired with March's Advanced Organic Chemistry for deeper mechanistic context. The supplementary data from OrgSyn comes up more often than people expect because it gives you experimental conditions rather than abstracted summary statements. Those experimental details are what separate a usable table from a decoration on your wall.

What most tables get wrong

The biggest problem with published reagent tables is that they present reagents as interchangeable when they are not. Two reducing agents might both reduce a ketone to an alcohol, but the choice between LiAlH4 and NaBH4 depends entirely on whether other functional groups in your molecule will survive the stronger reagent. A beginner will often pick the stronger reagent because the table entry looks more complete, then spend three days purifying a product that contains multiple unwanted reduction byproducts. Another issue is the omission of solvent effects. A reagent that works in THF at reflux may do nothing in toluene at the same temperature. The solvent is not just a passive medium. It stabilizes intermediates, affects solubility of reagents and byproducts, and changes the effective nucleophilicity or basicity of species in solution. I added a dedicated solvent column to my table after spending a week troubleshooting a reaction that worked flawlessly in one solvent system and failed completely in another that the literature cited as equivalent. The difference turned out to be coordination chemistry, not polarity. Scale matters too. Table entries almost never mention scale-dependent behavior, but reagents that work fine at milligram scale can behave unpredictably at gram scale or above. Exotherms become harder to control. Solubility limits that were invisible at small scale become the dominant constraint. I learned this the hard way with a Grignard reaction where the addition rate that worked at 0.1 mmol required complete redesign at 10 mmol because the exotherm ran away and decomposed a significant portion of the product.

How I use the table during actual work

I do not read through the whole table before a project. I go to the specific section relevant to the transformation I am planning. If I need to reduce a nitro group without touching a nearby ester, I look at the reducing agent section and scan for selectivity notes rather than general reactivity. The limitations column is where most of the useful information lives. That is the column that tells me zinc dust in ammonium chloride will hit the nitro group selectively while leaving the ester intact, something a basic reactivity chart would not convey. When planning multi-step sequences, I cross-reference reagent compatibility across steps. A protecting group strategy that looks fine in isolation can fall apart when you realize the deprotection conditions in step three are incompatible with a functional group introduced in step one. The table helps with this if you include notes about orthogonal compatibility. I mark each reagent with symbols for acid sensitivity, base sensitivity, and oxidative or reductive susceptibility. This makes it faster to spot conflicts without rereading full condition descriptions. The table is also useful for teaching and lab handover. When someone new joins the group, I point them to the relevant section rather than explaining reagent choices from scratch every time. It standardizes the decision-making process and reduces the chance that someone picks a reagent based on name recognition rather than functional group tolerance.

Practical tips for maintaining the table

Update it continuously. Every time you run a reaction that behaves differently from what the table says, or that reveals a new incompatibility, add a note. I keep a separate sheet for experimental anomalies and review it weekly when I have a moment. The accumulated notes eventually get incorporated into the main table entries as footnotes or condition modifiers. A static table becomes unreliable within a few months because your own observations contradict the textbook version. Include the commercial source or supplier in a column. Not because sourcing is the main concern, but because different suppliers sometimes supply the same reagent at different purity levels, and that difference shows up in yield and reproducibility. I have seen reactions fail repeatedly with reagent from one lot before succeeding once I switched to a different supplier with the same stated purity grade. Version your file. Date the filename or keep revision notes in a header row. You will forget which version contains the most recent updates, and working from an outdated entry is worse than working from no table at all.

The real value of a reagent table is not the volume of information it contains. It is the accuracy of the limitations and the speed with which you can find a compatible reagent for a specific transformation. A smaller, carefully maintained table beats a comprehensive one that you stop using because it is too slow to navigate or too inaccurate to trust.