Sodium Triethylborohydride-Iron(II) Chloride

NaEt3BH-FeCl2
(NaEt3BH)

[17979-81-6]  · C6H16BNa  · Sodium Triethylborohydride-Iron(II) Chloride  · (MW 122.02) (FeCl2)

[7758-94-3]  · Cl2Fe  · Sodium Triethylborohydride-Iron(II) Chloride  · (MW 126.75)

(reducing agent for thiols;1 can dimerize diaryl thioketones2)

Form Supplied in: Iron(II) Chloride is supplied in anhydrous form as a white powder. Sodium triethylborohydride is available as a 1 M solution in diethyl ether, THF, or toluene.

Desulfurization.

Thiols may be desulfurized to their parent hydrocarbons by the action of a mixture of FeCl2 and NaEt3BH (eq 1). Normally, a solution of the thiol (1.5 mmol) in THF (2-3 mL) is added to anhydrous FeCl2 (3.0 mmol) in THF (2 mL). THF (8 mL) is added, and after stirring for a short time period, the solution is added to a 1 M solution of NaEt3BH (6 mmol) in THF at -78 °C. An option exists where the NaEt3BH mixed with Alumina allows room temperature reactions and a more convenient reaction workup,2 but results in some cases in increased amounts of dimerization side products.

Dimerization of Diaryl Thioketones.

Diaryl thioketones undergo dimerization to tetraarylalkenes by NaEt3BH-FeCl2 on alumina (eq 2).2 These heterogeneous conditions give results superior to the homogeneous ones, where a significant amount of reduction to the diarylalkane competes with the desired reaction.


1. Alper, H.; Prince, T. L. AG(E) 1980, 19, 315; AG 1980, 92, 321.
2. Alper, H.; Ripley, S.; Prince, T. L. JOC 1983, 48, 250.

James R. Green

University of Windsor, Ontario, Canada



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