{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T00:26:41Z","timestamp":1791505601585,"version":"4.3.4"},"reference-count":26,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2017,10,17]],"date-time":"2017-10-17T00:00:00Z","timestamp":1508198400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Chiral N-protected \u03b1-amino aryl-ketones are one of the useful precursors used in the synthesis of various biologically active compounds and can be constructed via Friedel\u2013Crafts acylation of N-protected \u03b1-amino acids. One of the drawbacks of this reaction is the utilization of toxic, corrosive and moisture-sensitive acylating reagents. In peptide construction via amide bond formation, N-hydroxysuccinimide ester (OSu), which has high storage stability, can react rapidly with amino components and produces fewer side reactions, including racemization. This study reports the first synthesis and utilization of N-trifluoroacetyl (TFA)-protected \u03b1-amino acid-OSu as a potential acyl donor for Friedel\u2013Crafts acylation into various arenes. The TFA-protected isoleucine derivative and its diastereomer TFA-protected allo-isoleucine derivative were investigated to check the retention of \u03b1-proton chirality in the Friedel\u2013Crafts reaction. Further utilization of OSu in other branched-chain and unbranched-chain amino acids results in an adequate yield of TFA-protected \u03b1-amino aryl-ketone without loss of optical purity.<\/jats:p>","DOI":"10.3390\/molecules22101748","type":"journal-article","created":{"date-parts":[[2017,10,17]],"date-time":"2017-10-17T11:14:35Z","timestamp":1508238875000},"page":"1748","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Synthesis of Chiral TFA-Protected \u03b1-Amino Aryl-Ketone Derivatives with Friedel\u2013Crafts Acylation of \u03b1-Amino Acid N-Hydroxysuccinimide Ester"],"prefix":"10.3390","volume":"22","author":[{"given":"Zetryana","family":"Tachrim","sequence":"first","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuhiro","family":"Oida","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haruka","family":"Ikemoto","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fumina","family":"Ohashi","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natsumi","family":"Kurokawa","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kento","family":"Hayashi","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mami","family":"Shikanai","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuko","family":"Sakihama","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuyuki","family":"Hashidoko","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Makoto","family":"Hashimoto","sequence":"additional","affiliation":[{"name":"Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo 060-8589, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,10,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7002","DOI":"10.1021\/jo010414q","article-title":"Facile approach to enantiomerically pure \u03b1-amino ketones by Friedel\u2013Crafts aminoacylation and their conversion into peptidyl ketones","volume":"66","author":"Leggio","year":"2001","journal-title":"J. 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