Monatshefte f€ ur Chemie 136, 1583–1589 (2005) DOI 10.1007/s00706-005-0351-6 CsF-Celite, an Efficient Solid State Reagent for the Syntheses of Thioesters and Thioethers Syed T. A. Shah 1 , Khalid M. Khan 2 , Hidayat Hussain 2 , Safdar Hayat 2 , and Wolfgang Voelter 1; 1 Abteilung f€ ur Physikalische Biochemie des Physiologisch-chemischen Instituts der Universit € at T€ ubingen, D-72076 T€ ubingen, Germany 2 HEJ Research Institute of Chemistry, International Center for Chemical Sciences, University of Karachi, Karachi 75270, Pakistan Received December 3, 2004; accepted January 14, 2005 Published online August 10, 2005 # Springer-Verlag 2005 Summary. Coupling reactions of a number of aliphatic, aromatic, and heterocyclic compounds bearing an acidic hydrogen atom attached to sulfur, with alkyl, acyl, benzyl, or benzoyl halides in acetonitrile with cesium fluoride-Celite are described. This procedure is convenient, efficient, and practical for the preparation of thioethers and thioesters. Keywords. Cesium fluoride-Celite, Thioethers, Thioesters. Introduction A variety of organic reactions have recently been reported to be catalysed by cesium fluoride-Celite. The syntheses of carboxylic esters [1], -lactones [2], N- alkylation of anilines, carboxamides, and nitrogen heterocyclic compounds [3], and ring opening of epoxides [4] are among the reactions which are facilitated. The importance of the fluoride ion as a catalyst for the promotion of various types of base-catalyzed reactions in organic synthesis has been previously recog- nized [5–8]. In particular, the work of Clark and Miller [9–12] revealed that the fluoride ion effects the coupling reaction because of its high capability of hydrogen bond formation. As reagents, generating fluoride ions, potassium [6], cesium [1], and tetraalkylammonium fluorides were used so far. However, it is not easy to handle these hygroscopic reagents and the reproducibility of these reactions is in- variably poor. Recently, poorly hygroscopic reagents generating fluoride ions were designed allowing cesium fluoride to be absorbed on Celite [1]. The effect of  Corresponding author. E-mail: wolfgang.voelter@uni-tuebingen.de