OLOFSON Reagent

OLOFSON Reagent 279 OPPENALIER Oxidation 280 OPPOLZER Chiral reagent 281 Ortoleva 218... 

Woodward s reagent K is N-ethyl-3-phenylisoxazolium-3 -sulfonate, a zero-length cross-linking agent able to cause the condensation of carboxylates and amines to form amide bonds (Woodward et al., 1961 Woodward and Olofson, 1961). The reaction... 

Olofson and coworkers also introduced vinyl chloroformate as a reagent for the N-dealkylation of tertiary amines (Ref. 157,158,159). Compared with commonly utilized reagents in N-dealkylation procedures, the use of VOC-CI leads to significantly improved yields under milder conditions combined with greater discrimination between alkyl groups in unsymmetrical amines. The procedure is illustrated by the selective N-deethylation of N-ethyl piperidine to afford piperidine.HCI in 90% yield (Ref. 159) as depicted in scheme 107. 

Olofson and Martz have developed numerous applications of ACE-CI to the N-dealkylation of significant tertiary amines, especially in the field of analgesics and narcotic antagonists alkaloids, for example in a brilliant synthesis of Nalbuphine from Oxycodone in 69 % overall yield (Ref. 191). The scope and limitations of ACE-CI as a new reagent for the selective, high-yield N-dealkylation of tertiary amines will be examined in section 4-5 of voi. 2. 

Finally, I would particularly like to acknowledge Professor Roy Olofson (The Pennsylvania State University) for his unfailing enthusiastic support during our more than ten years collaboration on the development of new synthetic reagents and preparative methods in phosgene and related compounds chemistry. I am deeply grateful to him for his patience, wisdom and kidness and for being a model as a scientist and a teacher. 

Olofson, R. A. New, useful reactions of novel haloformates and related reagents. PureAppl. Chem. 1988, 60, 1715-1724. 

Isoxazolium method, peptide bond formation using N-ethyl-5-phenylisoxazolium-3 -sulfonate (Woodward reagent K) forming an end ester with N-protected amino acids and peptides which reacts in situ with the amino component providing the desired product beside a water-soluble aryl sulfonate as a byproduct that is easy to separate [R. B. Woodward, R. A. Olofson. J. Am. Chem. Soc. 1961, 83,1010]. 

Olofson, R.A., Martz, J.T., Senet J.-P. et a/. (1984) A new reagent for the selective, high-yield A-dealkylation of tertiary-amines - improved synthesis of naltrexone and nalbuphine. The Journal of Organic Chemistry, 49, 2081-2082. 

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