US EPA

2857243 

Journal Article 

Substrate dependent reaction channels of the Wolff-Kishner reduction reaction: A theoretical study 

Yamabe, S; Zeng, G; Guan, W; Sakaki, S 

2014 

Yes 

Beilstein Journal of Organic Chemistry
ISSN: 1860-5397 

10 

259-270 

English 

24605145 

10.3762/bjoc.10.21 

WOS:000330835700001 

https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893361016&doi=10.3762%2fbjoc.10.21&partnerID=40&md5=a6c5b4dd5d02f68af61a4af37d0552b9
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Wolff-Kishner reduction reactions were investigated by DFT calculations for the first time. B3LYP/6-311+G(d,p) SCRF=(PCM, solvent = 1,2-ethanediol) optimizations were carried out. To investigate the role of the base catalyst, the base-free reaction was examined by the use of acetone, hydrazine (H2N-NH2) and (H2O)8. A ready reaction channel of acetone → acetone hydrazine (Me2C=N-NH2) was obtained. The channel involves two likely proton-transfer routes. However, it was found that the base-free reaction was unlikely at the N2 extrusion step from the isopropyl diimine intermediate (Me2C(H)-N=N-H). Two base-catalyzed reactions were investigated by models of the ketone, H2N-NH2 and OH(-)(H2O)7. Here, ketones are acetone and acetophenone. While routes of the ketone → hydrazone → diimine are similar, those from the diimines are different. From the isopropyl diimine, the N2 extrusion and the C-H bond formation takes place concomitantly. The concomitance leads to the propane product concertedly. From the (1-phenyl)ethyl substituted diimine, a carbanion intermediate is formed. The para carbon of the phenyl ring of the anion is subject to the protonation, which leads to a 3-ethylidene-1,4-cyclohexadiene intermediate. Its [1,5]-hydrogen migration gives the ethylbenzene product. For both ketone substrates, the diimines undergoing E2 reactions were found to be key intermediates.