THE JOURNAL OF
Organic Chemistry 0 Cogyrighl 1965 by the American Chemical Socicly
VOLUME 30, NUMBER 9
SEPTEMBER 13, 1965
The Reduction of Oximes with Diborane. A New Synthesis of N-Monosubstituted Hydroxylamines H. FEUER,B. F. VINCENT,JR., AND R. S. BARTLETT Department of Chemistry, Purdue University, Lafayetie, Indiana Received May 10, 1966 The reactions of diborane with aliphatic aldoximes and ketoximes lead to intermediates which on basic or acidic hydrolysis afford exclusively the corresponding N-monosubstituted hydroxylamines in yields of 50-90%. The intermediates from the reaction of diborane with a-aryl aldoximes and ketoximes give only on acid hydrolysis the desired hydroxylamines. On basic hydrolysis they disproportionate into amines and oximes.
Reactions of multiple bonds by diborane have been widely explored' and include such groups as olefins, acetylenes, nitriles, carbonyl functions, and amides.2 From these data it seemed quite likely that oximes would also be reduced by diborane. This expectation proved to be correct, for treatment of ketoximes and aldoximes with diborane in tetrahydrofuran gave the corresponding N-monosubstituted hydroxylamines.a
1. BtHs
R--C--N--OH
k'
2. hydrolysis
R-CHNHOH
k'
R = H, alkyl, or aryl; R' = H or alkyl
A survey of the literature revealed that no general method was available for the preparation of N-monosubstituted hydroxylamines. Vavon and co-workers reported that catalytic hydrogenation of aliphatic and alicyclic ketoximes'-* led to the corresponding Nmonosubstituted hydroxylamines. On the other hand the catalytic reduction of a-phenyl ketoximes, such as acetophenone oxime and benzophenone oxime, gave the corresponding amines,g while the reduction of alkyl and aryl aldoximes afforded N,N-disubstituted hydroxylamine^.^ Other methods of preparing Nmonosubstituted hydroxylamines include electrolytic reduction of primary and secondary nitroalkanes,"JJ1 (1) H. C. Brown, "Hydroboretion," W. A. Benjamin, h a . , New York,
N. Y.,1962. (2) H. C. Brown and P. Heim, J . Am. Chem. Soc., 86, 3566 (1904). (3) A preliminary announcement of this work haa appeared: H. Feuer and B. F. Vincent, Jr., J . Am. Chem. SOC.,84, 3771 (1902). (4) G. Vavon and A. L. Berton, BUU. 8oc. chim. France, 87, 301 (1925). (5) G. Vavon and A. C d e r ,
