4-(Dimethylamino)pyridine, 99%, Thermo Scientific Chemicals

General References:

1. Hypernucleophilic catalyst. Greatly accelerates the acylation of hindered, including tertiary, alcohols; reviews: Angew. Chem. Int. Ed., 17, 569 (1978). Chem. Soc. Rev., 12, 129 (1983). Catalyst for acylation of alcohols using mixed anhydrides of hindered carboxylic acids with methanesulfonic acid: Synth. Commun., 12, 727 (1982), and with mixed carboxylic anhydrides: J. Org. Chem., 50, 560 (1985). In the Yamaguchi method of macrocyclic lactonization the mixed anhydride formed with 2,4,6-Trichlorobenzoyl chloride, L14159 is cyclized with 2 equiv. of DMAP; high dilution conditions are not required: Bull. Chem. Soc. Jpn., 52, 1989 (1979). For improved method in a high yield synthesis of erythronolide A, see: J. Org. Chem., 55, 7 (1990).
2. Greatly increases the rate of ester and thio ester formation in the carbodiimide method of coupling (Steglich esterification): Angew. Chem. Int. Ed., 17, 522 (1978). For similar use in macrolactonizations, see: J. Org. Chem., 50, 2394 (1985), and in carbodiimide peptide coupling reactions: Int. J. Pept. Prot. Res., 18, 459 (1981). For peptide reagents, see Appendix 6.
3. Effective catalyst for transesterification of ß-keto esters in toluene: J. Org. Chem., 50, 3618 (1985), and for smooth decarboalkoxylation of enolizable ß-keto esters in toluene containing a small amount of water: J. Org. Chem., 54, 3474 (1989). Under these conditions, other bases (N,N-dimethylaniline, pyridine, tetra-n-pentylammonium bromide) are ineffective.