{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T01:19:42Z","timestamp":1775179182831,"version":"3.50.1"},"reference-count":30,"publisher":"Wiley","issue":"35","license":[{"start":{"date-parts":[[2007,10,11]],"date-time":"2007-10-11T00:00:00Z","timestamp":1192060800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["chemistry-europe.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Eur J Org Chem"],"published-print":{"date-parts":[[2007,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>We have developed a modification of our previously reported high\u2010yielding method for the synthesis of <jats:italic>N<\/jats:italic>,<jats:italic>N<\/jats:italic>\u2010diacyldehydroamino acid derivatives to prepare <jats:italic>N<\/jats:italic>\u2010monoprotected dehydroamino acids and dehydrodipeptides. Thus, several dehydroalanine, dehydroaminobutyric acid and dehydrophenylalanine derivatives have been prepared by treating the corresponding <jats:sc>L<\/jats:sc>\u2010serine, <jats:sc>L<\/jats:sc>\u2010threonine and <jats:sc>D<\/jats:sc>,<jats:sc>L<\/jats:sc>\u20103\u2010phenylserine (<jats:italic>threo<\/jats:italic>\u2010type) derivatives with 1 equiv. of di\u2010<jats:italic>tert<\/jats:italic>\u2010butyl dicarbonate and 4\u2010(dimethylamino)pyridine. The reaction proceeded with the initial formation of an <jats:italic>O<\/jats:italic>\u2010<jats:italic>tert<\/jats:italic>\u2010butyl carbonate which, by treament with <jats:italic>N<\/jats:italic>,<jats:italic>N<\/jats:italic>,<jats:italic>N\u2032<\/jats:italic>,<jats:italic>N\u2032<\/jats:italic>\u2010tetramethylguanidine, underwent \u03b2 elimination to give the corresponding dehydroamino acid derivative. This two\u2010step method can be carried out as a one\u2010pot procedure and is stereoselective, giving only the <jats:italic>Z<\/jats:italic> isomer. The <jats:italic>N<\/jats:italic>\u2010monoprotected dehydroamino acids were treated with <jats:italic>N<\/jats:italic>\u2010bromosuccinimide and thereafter with triethylamine to afford several \u03b2,\u03b2\u2010dibromodehydroalanines or \u03b2\u2010bromo\u2010, \u03b2\u2010alkyl\u2010 or \u03b2\u2010aryldehydroalanines. The latter were obtained as mixtures of <jats:italic>E<\/jats:italic> and <jats:italic>Z<\/jats:italic> isomers. An increased stereoselectivity towards the formation of the <jats:italic>Z<\/jats:italic> isomer was observed with dehydrophenylalanine and when 4\u2010tolylsulfonyl was used as the <jats:italic>N<\/jats:italic>\u2010protecting group. In the case of dehydrodipeptides, the reaction with NBS and triethylamine afforded the corresponding brominated dehydrodipeptides when the <jats:italic>N<\/jats:italic>\u2010protecting group was other than 4\u2010tolylsulfonyl. However, when the reagent was a peptide with a dehydroamino acid as the second residue and an <jats:italic>N<\/jats:italic>\u2010(4\u2010tolylsulfonyl) group the corresponding 2,2\u2010disubstituted 1\u2010(4\u2010tolylsulfonyl)imidazolidin\u20104\u2010ones were obtained in good\u2010to\u2010high yields. (\u00a9 Wiley\u2010VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2007)<\/jats:p>","DOI":"10.1002\/ejoc.200700669","type":"journal-article","created":{"date-parts":[[2007,10,11]],"date-time":"2007-10-11T09:47:52Z","timestamp":1192096072000},"page":"5934-5949","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":41,"title":["Reactivity of Dehydroamino Acids and Dehydrodipeptides Towards <i>N<\/i>\u2010Bromosuccinimide: Synthesis of \u03b2\u2010Bromo\u2010 and \u03b2,\u03b2\u2010Dibromodehydroamino Acid Derivatives and of Substituted 4\u2010Imidazolidinones"],"prefix":"10.1002","volume":"2007","author":[{"given":"Paula M. T.","family":"Ferreira","sequence":"first","affiliation":[]},{"given":"Lu\u00eds S.","family":"Monteiro","sequence":"additional","affiliation":[]},{"given":"Goreti","family":"Pereira","sequence":"additional","affiliation":[]},{"given":"Liliana","family":"Ribeiro","sequence":"additional","affiliation":[]},{"given":"Joana","family":"Sacramento","sequence":"additional","affiliation":[]},{"given":"Liseta","family":"Silva","sequence":"additional","affiliation":[]}],"member":"311","published-online":{"date-parts":[[2007,11,26]]},"reference":[{"key":"e_1_2_6_1_2","doi-asserted-by":"publisher","DOI":"10.1039\/a904730a"},{"key":"e_1_2_6_2_2","first-page":"1","author":"Bonauer C.","year":"2006","journal-title":"Synthesis"},{"key":"e_1_2_6_3_2","unstructured":"\u00a0"},{"key":"e_1_2_6_4_2","first-page":"3317","author":"Maia H. L. S.","year":"2000","journal-title":"J. Chem. Soc. Perkin Trans. 1"},{"key":"e_1_2_6_5_2","doi-asserted-by":"publisher","DOI":"10.1039\/b106487h"},{"key":"e_1_2_6_6_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.200600094"},{"key":"e_1_2_6_7_2","unstructured":"\u00a0"},{"key":"e_1_2_6_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(02)00810-9"},{"key":"e_1_2_6_9_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.200300103"},{"key":"e_1_2_6_10_2","unstructured":"\u00a0"},{"key":"e_1_2_6_11_2","doi-asserted-by":"crossref","first-page":"3377","DOI":"10.1016\/S0040-4039(03)00709-3","volume":"44","author":"Silva N. O.","year":"2003","journal-title":"Tetrahedron Lett."},{"key":"e_1_2_6_12_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2004.09.107"},{"key":"e_1_2_6_13_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00891a019"},{"key":"e_1_2_6_14_2","doi-asserted-by":"publisher","DOI":"10.1246\/bcsj.45.1162"},{"key":"e_1_2_6_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00433a014"},{"key":"e_1_2_6_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00433a015"},{"key":"e_1_2_6_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/0040-4039(95)00459-P"},{"key":"e_1_2_6_18_2","unstructured":"W. A. Nugent PCT Int. Appl. W09616021 (Cl C07C231\/14) US Appl. 34078117 1996[Chem. Abstr.1996 143302k ]."},{"key":"e_1_2_6_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(00)97458-6"},{"key":"e_1_2_6_20_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0960-894X(01)00187-1"},{"key":"e_1_2_6_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(00)74743-5"},{"key":"e_1_2_6_22_2","unstructured":"\u00a0"},{"key":"e_1_2_6_23_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.200300394"},{"key":"e_1_2_6_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tet.2006.12.084"},{"key":"e_1_2_6_25_2","doi-asserted-by":"publisher","DOI":"10.1016\/0040-4020(96)00209-8"},{"key":"e_1_2_6_26_2","first-page":"1489","author":"Brown A. G.","year":"1969","journal-title":"J. Chem. Soc. C"},{"key":"e_1_2_6_27_2","doi-asserted-by":"publisher","DOI":"10.1002\/1099-0690(200208)2002:15<2524::AID-EJOC2524>3.0.CO;2-W"},{"key":"e_1_2_6_28_2","doi-asserted-by":"publisher","DOI":"10.1080\/15533170500360446"},{"key":"e_1_2_6_29_2","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1111\/j.1399-3011.1979.tb01870.x","volume":"13","author":"Sannama L.","year":"1979","journal-title":"Int. J. Pept. Protein Res."},{"key":"e_1_2_6_30_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.19850970626"}],"container-title":["European Journal of Organic Chemistry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fejoc.200700669","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ejoc.200700669","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T16:33:17Z","timestamp":1760545997000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/ejoc.200700669"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,11,26]]},"references-count":30,"journal-issue":{"issue":"35","published-print":{"date-parts":[[2007,12]]}},"alternative-id":["10.1002\/ejoc.200700669"],"URL":"https:\/\/doi.org\/10.1002\/ejoc.200700669","archive":["Portico"],"relation":{},"ISSN":["1434-193X","1099-0690"],"issn-type":[{"value":"1434-193X","type":"print"},{"value":"1099-0690","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,11,26]]},"assertion":[{"value":"2007-07-20","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2007-11-26","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}