741 Synthesis of fluorescent (benzyloxycarbonylamino)(aryl)methylphosphonates Michał Górny vel Górniak 1,2 , Anna Czernicka 1 , Piotr Młynarz 1 , Waldemar Balcerzak 3 and Paweł Kafarski *1,2 Full Research Paper Open Access Address: 1 Department of Bioorganic Chemistry, Faculty of Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland, 2 Department of Chemistry, University of Opole, pl. Kopernika 11a, 45-040 Opole, Poland and 3 First Department of General, Gastroenterological and Endocrinological Surgery, Wroclaw Medical University, ul. Marii Skłodowskiej-Curie 66, 50-369 Wrocław, Poland Email: Paweł Kafarski * - pawel.kafarski@pwr.wroc.pl * Corresponding author Keywords: aminophosphonates; Oleksyszyn reaction; organophosphorus; Z-aminophosphonate esters Beilstein J. Org. Chem. 2014, 10, 741–745. doi:10.3762/bjoc.10.68 Received: 04 December 2013 Accepted: 12 March 2014 Published: 28 March 2014 This article is part of the Thematic Series "Organophosphorus chemistry". Guest Editor: P. R. Hanson © 2014 Górniak et al; licensee Beilstein-Institut. License and terms: see end of document. Abstract The synthesis of a library of structurally variable aromatic esters of (benzyloxycarbonylamino)(aryl)methylphosphonic acids is described by means of the Oleksyszyn reaction. The library was enlarged by the application of a Suzuki–Miayra approach and by preparation of mixed esters. 741 Introduction Screening of the activity of large libraries of fluorogenic substrates of chosen enzymes is an emerging approach to deter- mine their substrate preferences and thus to provide a set of data useful for the preparation of their selective inhibitors [1-5]. Such fluorogenic probes have been also used for profiling the proteolytic secretomes with the obtained profiles being useful as diagnostic tools [6-8]. Also conjugates of drugs with fluores- cent probes have been used as so called theranostics (combina- tion of therapeutics and diagnostics) [9,10]. Diaryl esters of α-aminoalkanephosphonic acids and their short peptides are a class of well-established inhibitors of serine proteases [11,12]. Their mechanism of action involves phospho- nylation of the active-site of these enzymes with simultaneous release of the appropriate phenol [13,14]. Therefore, the syn- thesis of such inhibitors carrying fluorescent probes in their side chains or in the ester phosphonate moieties might find an appli- cation in constructing fluorescent probes for studying structural requirements of enzymes having serine in their active sites