Schwartz's reagent

Schwartz's reagent

Names
IUPAC name chloridobis(η5-cyclopentadienyl)hydridozirconium
Other names Cp2ZrClH, zirconocene chloride hydride
Identifiers
CAS Number	37342-97-5
3D model (JSmol)	Interactive image
ChemSpider	28605366
ECHA InfoCard	100.048.599
InChI InChI=1S/2C5H5.ClH.Zr.H/c2*1-2-4-5-3-1;;;/h2*1-5H;1H;;/q2*-1;;+3;/p-1 Key: GBJQOFBMEJYDAU-UHFFFAOYSA-M InChI=1/2C5H5.ClH.Zr.H/c2*1-2-4-5-3-1;;;/h2*1-5H;1H;;/q2*-1;;+3;/p-1/r2C5H5.ClHZr/c2*1-2-4-5-3-1;1-2/h2*1-5H;2H/q2*-1;+2 Key: GBJQOFBMEJYDAU-CFXPZLBWAB
SMILES [cH-]1cccc1.[cH-]1cccc1.Cl[ZrH+2]
Properties
Chemical formula	C10H11ClZr
Molar mass	257.87 g/mol
Appearance	White solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Schwartz's reagent is the common name for the chemical compound with the formula (C₅H₅)₂ZrHCl, sometimes called zirconocene hydrochloride or zirconocene chloride hydride, and is named after Jeffrey Schwartz, a chemistry professor at Princeton University. This metallocene is used in organic synthesis for various transformations of alkenes and alkynes.

The complex was first prepared by Wailes and Weigold. It can be purchased or readily prepared by reduction of zirconocene dichloride with lithium aluminium hydride:

In practice this reaction also affords (C₅H₅)₂ZrH₂, which is treated with methylene chloride to give the mixed hydride chloride. An alternative procedure that generated Schwartz's Reagent from dihydride has also been reported.

Schwartz's reagent can be used for a number of reactions. It has been shown that it can be used to reduce amides to aldehydes. Reducing tertiary amides with Schwartz's reagent can reach efficient yields, but primary and secondary amides will show decreased yields. The use of Schwartz's reagent in this manner will not require any added heat and can be done quickly, and reduction of the alcohol form is not a problematic side reaction as it can be with other reducing agents. Schwartz's reagent will selectively reduce the amide over any readily reducible esters that may be present in the reaction mixture.

Vinylation of ketones in high yields is a possible use of Schwartz's reagent.

Schwartz's reagent is used in the synthesis of some macrolide antibiotics, (−)-motuporin, and antitumor agents.