Cadmium Chloride

CdCl2

[10108-64-2]  · CdCl2  · Cadmium Chloride  · (MW 183.31)

(organocadmium reagents are useful in the synthesis of keto esters,2 in regioselective,3 stereoselective4 addition reactions, and in osmium-catalyzed hydroxylation;5 CdCl2 is useful in ring opening6 and oxidation7-11 reactions)

Physical Data: mp 568 °C; d 4.047 g cm-3.

Solubility: insol ether; slightly sol methanol, ethanol; sol acetone; freely sol water.

Form Supplied in: white crystalline solid; widely available. Drying: for some applications the cadmium chloride must be anhydrous. The recommended procedure involves drying to a constant weight at 110 °C in an oven, grinding throughly, and storing in a desiccator.

Handling, Storage, and Precautions: should be stored in a dry place. It is a highly toxic cancer suspect agent and should be handled carefully.

Organocadmium Reagents.

Cadmium chloride is most often used to prepare organocadmium compounds. Use of organocadmium derivatives for the preparation of simple ketones was introduced as early as 1936.1 Alkyl organocadmium derivatives, prepared by reaction of the corresponding RMgBr compounds with anhydrous CdCl2 in ether, react with a variety of ester acid chlorides to give keto esters (eq 1).2

Lithium enolates of a,b-unsaturated esters condense cleanly with aldehydes, affording the a product exclusively. This is in accordance with the normal regiochemical behavior of vinylogous anions. Use of organocadmium reagents prepared in situ from their lithium derivatives reverses the regioselectivity (eq 2).3

Cadmium chloride mediated addition of organometallics to chiral a-keto amides influences the stereochemistry of the reaction (eq 3).4

N-Chloro-N-cadmium carbamates can be generated in situ by reaction of the corresponding N-chloro sodiocarbamates with cadmium chloride in acetonitile. These organocadmium reagents are useful in an osmium-catalyzed procedure which effects cis addition of hydroxyl and carbamate moieties across an alkenic linkage (eq 4).5

Synthetically useful cadmium homoenolates have been prepared by the heterometalation-type ring cleavage of electron-rich cyclopropanes by cadmium chloride under ultrasonic irradiation at room temperature (eq 5).6

Oxidations.

In the synthesis of polycyclic aromatics, dehydrogenations are effectively carried out using cadmium chloride as an oxidizing agent (eqs 6 and 7).7,8

Cadmium chloride has been employed as an oxidizing agent in the conversion of 1,5-cyclooctadiene to cyclooctatetraene through the intermediacy of cyclooctatetraenyl dianion (eq 8).9-11


1. Gilman, N. RTC 1936, 55, 518.
2. Cason, J.; Prout, F. S. OSC 1955, 3, 601.
3. Lei, B.; Fallis, A. G. CJC 1991, 69, 1450.
4. Fujisawa, T.; Ukaji, T.; Funabora, M.; Yamashita, M.; Sato, T. BCJ 1990, 63, 1894.
5. Herranz, E.; Sharpless, K. B. JOC 1980, 45, 2710.
6. Nakamura, E.; Shimada, J.; Kuwajima, I. OM 1985, 4, 641.
7. Harvey, L.; Nazareno, L.; Cho, H. JACS 1973, 95, 2378.
8. Bohm, A.; Meerholz, K.; Heinze, J.; Mullen, K. JACS 1992, 114, 688.
9. Antkowiak, T. A.; Shechter, H. JACS 1972, 94, 5361.
10. Meyer, N.; Seebach, D. AG 1978, 90, 553.
11. Evans, W. J.; Wink, D. J.; Wayda, A. L.; Little, D. A. JOC 1981, 46, 3925.

Nachimuthu Soundararajan

Bristol-Myers Squibb Pharmaceutical Research Institute, New Brunswick, NJ, USA



Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.