•
For ester or thioester formation from an acid and an alcohol, the rate is greatly increased by addition of 4-(Dimethylamino)pyridine, A13016: Angew. Chem. Int. Ed., 17, 522 (1978). For t-butyl esters, see: Org. Prep. Proced. Int., 20, 180 (1988); Org. Synth. Coll., 7, 93 (1990). The same combination has been found useful in macrolactonization reactions: J. Org. Chem., 50, 2394 (1985); and in formation of propynoic esters under mild conditions: Tetrahedron Lett., 30, 4575 (1989).•
DCC has also been used in dehydrations, e.g. carboxylic acids to anhydrides: J. Am. Chem. Soc., 85, 1997 (1963); J. Org. Chem., 54, 1922 (1989); primary amides: J. Org. Chem., 26, 3356 (1961), and aldoximes: Synth. Commun., 3, 101 (1973); 12, 25 (1982) to nitriles; dialkylacetic acids to ketenes (where stable): Synthesis, 568 (1989). The combination with Dimethyl sulfoxide, A13280, is used in the Pfitzner-Moffatt oxidation of alcohols to carbonyl compounds under mild conditions: J. Am. Chem. Soc., 85, 3027 (1963); 87, 5661, 5670 (1965); Org. Synth. Coll., 5, 242 (1973); review: Synthesis, 857 (1990).• In the presence of H2SO4 or AlCl3, Friedel-Crafts cyclohexylation of arenes has been reported: Tetrahedron Lett., 35, 903 (1994).
•
Promotes a variety of acylation reactions between carboxylic acids and nucleophiles; the dicyclohexylurea by-product is almost insoluble in most solvents:
•
DCC-coupling is frequently used to prepare active esters, e.g. of 4-Nitrophenol, A14376, or Pentafluorophenol, A15574, for peptide coupling; see Appendix 6.•
In peptide coupling reactions, various auxiliary reagents have been used to suppress racemization. See, e.g., N-Hydroxysuccinimide, A10312, N-Hydroxyphthalimide, A13862, and endo-N-Hydroxy-5-norbornene-2,3-dicarboximide, A13205. For use of CuCl2, see: Tetrahedron Lett., 25, 771 (1984); J. Chem. Soc., Chem. Commun., 419 (1988).• For reviews of advances in the chemistry of carbodiimides, see: Chem. Rev., 67, 107 (1967), 81, 589 (1981); Tetrahedron, 37, 233 (1981).
腐蚀性 (C)
有毒 (T)
有害性 (Xn)
