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Lindlar catalyst

Lindlar catalyst
Other names Palladium on calcium carbonate, poisoned
CAS number 7440-05-3
Molecular formula not a compound
Appearance Gray powder
MSDS External MSDS
Main hazards none
R-phrases R20 R33 R36 R37 R38
S-phrases S22 S27 S36 S37 S39
Related Compounds
Related compounds Palladium on carbon
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

A Lindlar catalyst is a heterogeneous catalyst that consists of palladium deposited on calcium carbonate and treated with various forms of lead. The lead additive serves to deactivate the palladium sites. A variety of "catalyst poisons" have been used including lead acetate and lead oxide. The palladium content of the catalyst is usually 5% by weight. The catalyst is used for the hydrogenation of alkynes to alkenes.

As described by its inventor,[1][2] the catalyst is prepared by reduction of palladium chloride in a slurry of calcium carbonate followed by adding lead acetate. By this approach, one obtains a catalyst with a large surface area. Further deactivation of the catalyst with quinoline enhances its selectivity, preventing formation of alkanes. An example of alkyne reduction is the reduction of phenylacetylene to styrene.[1]

Alkyne reduction is stereoselective, occurring via syn addition to give the cis-alkene.[3] The commercial organic synthesis of vitamin A also involves an alkyne reduction with the Lindlar catalyst.

Other heterogeneous catalysts useful for hydrogenation are Adam's Catalyst, Palladium Black, and Raney nickel.


  1. ^ a b Lindlar, H.; Dubuis, R. "Palladium Catalyst for Partial Reduction of Acetylenes" Organic Syntheses, Collected Volume 5, p.880 (1973).
  2. ^ Lindlar, H. "Ein neuer Katalysator für selektive Hydrierungen"; Helv. Chim. Acta 1952, 35, 446-450, doi:10.1002/hlca.19520350205.
  3. ^ Overman, L. E.; Brown, M. J.; McCann, S. F. "(Z)-4-(Trimethylsilyl)-3-Buten-1-ol" Organic Syntheses, Collected Volume 8, p.609 (1993).
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lindlar_catalyst". A list of authors is available in Wikipedia.
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