How does DMAP work as a catalyst?

A better explanation for DMAP being such an effective catalyst is that it reacts with acid chlorides, such as 12, to form high concentrations of N‑acylpyridinium salts (eq 7). These salts are better able to transfer an acyl group to a nucleophile than is the acid chloride itself.

Why is DMAP toxic?

Safety. DMAP has a relatively high toxicity and is particularly dangerous because of its ability to be absorbed through the skin. It is also corrosive.

What is DMAP soluble in?

SOLUBILITY: Soluble in methanol, benzene, ethyl acetate, chloroform, me- thylene chloride, acetone, and acetic acid. Less soluble in ether, diisopropyl ether, cyclohexane, hexane, and water.

How do I remove DMAP?

Like others have mentioned, DMAP is easy to remove by washing the crude mixture with 2N HCl, unless your product is basic in nature (in fact, since you usually use the catalytic amount of DMAP in combination with Et3N, acidic wash is a part of the standard work-up procedure).

What does DMAP do in a reaction?

DMAP is an acyl transfer reagent that reacts regioselectively at the less hindered carbonyl site: DMAP is a stronger nucleophile than the alcohol. The newly formed intermediate is less hindered, the acyl group is still polarized and DMAP is a good leaving group, all of which enable a fast reaction with the alcohol.

What is Yamaguchi reagent?

The Yamaguchi esterification is the chemical reaction of an aliphatic carboxylic acid and 2,4,6-trichlorobenzoyl chloride (TCBC, Yamaguchi reagent) to form a mixed anhydride which, upon reaction with an alcohol in the presence of stoichiometric amount of DMAP, produces the desired ester.

How do you neutralize pyridine?

To remove the trace amount of pyridine you can use toulene or water and remove solve under reduced pressure. I used and worked well. Unless your target compound is a pyridine derivative, use mild acidic solution (e.g. 1-5 % aq. HCl) during work-up.