CAS No 37342-97-5 , Bis(cyclopentadienyl)zirconium chloride hydride

Title: Schwartz's Reagent
CAS Registry Number: 37342-97-5
CAS Name: Chlorobis(h5-2,4-cyclopentadien-1-yl)hydrozirconium
Synonyms: Cp2Zr(H)Cl; (h5-C5H5)2Zr(H)Cl
Molecular Formula: C10H11ClZr
Molecular Weight: 257.87
Percent Composition: C 46.58%, H 4.30%, Cl 13.75%, Zr 35.38%
Literature References: Hydrozirconation reducing agent for a range of unsaturated compounds. Prepn: P. C. Wailes, H. Weigold, J. Organomet. Chem. 24, 405 (1970); with high yield: S. L. Buchwald et al., Tetrahedron Lett. 28, 3895 (1987); in situ prepn: B. H. Lipshutz et al., ibid. 31, 7257 (1990). Stereoselectivity: E. Cesarotti et al., Inorg. Chim. Acta 64, L207 (1982). Use as general reducing agent: J. Schwartz, J. A. Labinger, Angew. Chem. Int. Ed. 15, 333 (1976); reduction of halides in presence of triethylborane, q.v.: K. Fujita et al., J. Am. Chem. Soc. 123, 3137 (2001); in silylation of alkenes: J. Terao et al., Tetrahedron 60, 1301 (2004). Review of applications in phosphorous chemistry: J.-P. Majoral et al., Ber. 129, 879-886 (1996); of mechanism and reduction of amides: J. M. White et al., Chem. Innovation 30, 23-28 (2000).
Properties: White solid turning pink in light.
Use: Functionalization of unsaturated systems via an organozirconium intermediate.