Can be used to prepare Cs salts of N-protected amino acids or peptides, which can then be cleanly esterified by treatment with an alkyl halide in DMF: Helv. Chim. Acta, 56, 1476 (1973); J. Org. Chem., 42, 1286 (1977). Carboxylic acids can be esterified in high yield with an alkyl halide and Cs2CO3 at ambient temperature in DMF: Synth. Commun., 30, 2687 (2000). Benzoic acids can be esterified by refluxing with an alcohol in acetonitrile: Org. Prep. Proced. Int., 28, 480 (1996). The di-Cs salts of catechol and resorcinol are superior to other alkali metal salts in the reaction with dibromoethers in DMF to give crown ethers: J. Chem. Soc., Chem. Commun., 285 (1979). Also used in the facile synthesis of alkyl phenyl ethers from phenols and alkyl halides in acetonitrile: Synth. Commun., 25, 1367 (1995), and catalytically in the O-methylation of phenols by heating in excess dimethyl carbonate: Synlett, 1063 (1998); K2CO3 was found to be less effective. Indoles undergo N-alkylation in DMPU: Synlett, 2394 (2004).For use in formation of macrocyclic sulfides from dithiols and dibromoalkanes, see: J. Org. Chem., 46, 4481 (1981); Org. Synth. Coll., 8, 592 (1993). Salts of other metals are ineffective. For a review of the 'cesium ion effect' and macrocyclization, see: Org. Prep. Proced. Int., 24, 285 (1992). Superior base for Horner-Wadsworth-Emmons olefination reaction of phosphonates: Chem. Lett., 335 (1989); Bull. Soc. Chim. Belg., 100, 267 (1991). For cleavage of 2-oxazolidinones to give amino alcohols, see: Tetrahedron Lett., 28, 4185 (1987).For a brief feature on uses of the reagent in synthesis, see: Synlett, 2447 (2004).
