SYNTHESIS0039-78811437-210X © Georg Thieme Verlag Stuttgart · New York 2016, 48, 1301–1317 1301 feature Syn thesis J. Pletz et al. Feature A General and Direct Reductive Amination of Aldehydes and Ketones with Electron-Deficient Anilines Jakob Pletz EWG hydride reductant EWG H NH 1 N R1 Bernhard Berg 2 O R activating agent + Rolf Breinbauer* 2 R2 R Institute of Organic Chemistry, Graz University of Technology, 29 examples up to 99% yield Stremayrgasse 9, 8010 Graz, Austria 3 methods:
[email protected] A) BH3•THF, AcOH, CH2Cl2, 0–20 °C 12 anilines In memoriam Philipp Köck B) BH3•THF, TMSCl, DMF, 0 °C 14 ketones C) NaBH4, TMSCl, DMF, 0 °C 3 aldehydes Received: 01.12.2015 Our first goal was the design and synthesis of analogues Accepted after revision: 20.01.2016 of intermediates in the transformation catalyzed by the Published online: 01.03.2016 1 DOI: 10.1055/s-0035-1561384; Art ID: ss-2015-t0688-fa protein PhzA/B. According to Wulf’s proposal, this enzyme was expected to catalyze the imine formation between the putative aminoketone B, resulting from the transformation Abstract In our ongoing efforts in preparing tool compounds for in- of PhzF with dihydrohydroxyanthranilic acid (DHHA; A), vestigating and controlling the biosynthesis of phenazines, we recog- with itself, thereby establishing the tricyclic skeleton C, nized the limitations of existing protocols for C–N bond formation of from which after a series of oxidation reactions phenazine- electron-deficient anilines when using reductive amination. After ex- carboxylic acid E will