BARTON Deamination

BAMBERGER Benzotnazine synthesis 17 BAMFORD - STEVENS CAGLIOTI - SHAPIRO Reaction 18 BARBIER Reaction 19 BARBIER - VnlELAND DegradaUon 20 BART SCHEUER Arsonylation 21 BARTON Name photolysis 22 BARTON Deamination 23 BARTON Decarboxylation 24... 

Barton and Narang" have prepared nitrate esters by treating primary and secondary alky-lamines with dinitrogen tetroxide in the presence of an amidine base like DBU. Wudl and Lee " conducted deamination reactions without any amidine base and reported much lower yields of nitrate ester product. The use of an amidine base is not necessary if the amine substrate... 

D. H. R. Barton, D. O. Jang, and J. Cs. Jaszberenyi, The invention of radical reactions. Part XXXI. Diphenylsilane A reagent for deoxygenation of alcohols via their thiocarbonyl derivatives, deamination via isonitriles, and dehalogenation of bromo- and iodo-compounds by radical chain chemistry, Tetrahedron, 49 (1993) 7193-7214. 

The same polymer-supported organotin reagent was also used in the Barton-type deoxygenation of steroid derivatives, sugar derivatives and diols160. Furthermore, the radical deamination of secondary and tertiary amines via the corresponding isocyanides was also reported160,169. 

The Bu3SnH decyanation of isonitriles (Scheme 16) was first reported by Saegusa, and was developed as a general, mild method for reductive deamination by Barton and coworkers who initially showed that a variety of isonitriles, isothiocyanates and isoselenocyanates reacted with Bu3SnH under the usual free radical conditions (reflux in benzene, toluene or xylene with catalytic AIBN) to give good yields of the corresponding hydrocarbon. In concert with the normal order of radical stability, primary... 

Barton, D. H. R., Jang, D. O. and Jaszberenyi, J. C. (1993) The invention of radical reactions. Part 32. Radical deoxygenations, dehalogenations, and deaminations with dialkyl phosphites and hypophosphorous acid as hydrogen sources. J. Org. Chem., 58, 6838-6842. 

Chatgilialoglu studied (MesSijsGeH as a new radical hydrogen donor, and found that reduction of chlorides, bromides, and iodides, deoxygenation of secondary alcohols via a thiono ester (Barton-McCombie reaction), deamination of primary amines via isocyanides, removal of PhSe group, and replacement of a tertiary nitro group by hydrogen were extremely effective (Scheme 11.15) [31]. 

D.H.R. Barton, at MIT with H. G. Khorana and at Wesleyan University with Max Tishler. He has served on the chemistry faculties of Tufts University, New Mexico State University, and is currently Dishman Professor of Science at Southwestern University. He carried out sabbatical research in the Pharmaceutical Sciences Department at DeMontfort University, Leicester, UK with Laurence Patterson under a Fulbright Fellowship and with Henk Hiemstra at the University of Amsterdam. His scientific interests include the chemistry of organoselenium compounds, extrusion reactions, functionalizing deamination reactions, and sterically hindered molecules. Collaborating with his wife Lynn Guziec he is also involved in the design and synthesis of anticancer compounds. 

A novel method for the reductive deamination of amino-sugars has been published by Barton s group. The process involves sequential iV-formylation, dehydration to the isocyano-derivative, and reduction with tributylstannane. Application of the reaction to l,3,4,6-tetra-C>-acetyl-2-amino-2-deoxy-/3-D-gluco-pyranose afforded 2-deoxy-D-glucose tetra-acetate in 72% yield. 

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