Catalytic reagent which is both a potent base and a source of nucleophilic fluoride. Prepn as hydrated form: D. L. Fowler et al., J. Am. Chem. Soc. 62, 1140 (1940). Instability of anhydrous form: R. K. Sharma, J. L. Fry, J. Org. Chem. 48, 2112 (1983). Use as fluoride source: D. P. Cox et al., ibid. 49, 3216 (1984); T. Kobayashi et al., ibid. 67, 3156 (2002). Synthesis and/or use as catalyst in cyclization reactions: J. Pless, ibid. 39, 2644 (1974); A. R. Gangloff et al., Tetrahedron Lett. 42, 1441 (2001); in addition reactions: P. Molina et al., Synlett 2003, 714. Deprotecting agent: M. Namikoshi et al., J. Org. Chem. 56, 5464 (1991); J. J. Parlow et al., Bioorg. Med. Chem. Lett. 8, 2391 (1998). Brief review in cleavage of silyl protecting groups: M. B. Kumar, Synlett 2002, 2125-2126.