Sonogashira diversification of unprotected halotryptophans, halotryptophan containing tripeptides; and generation of a new to nature bromo-natural product and its diversification in water

The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013/ERC grant agreement no 614779 (to R.J.M.G), and ERAIB (Grant no. 031A338A)) (to R.J.M.G), and H2020-MSCA-IF-2014 (Grant no. 659399 (to C.P.U). We thank EPSRC National Mass Spectrometry Service Centre (Swansea, UK) for assistance in acquiring MS analysis on a number of the lower molecular weight tryptophan derivatives.The blending together of synthetic chemistry with natural product biosynthesis represents a potentially powerful approach to synthesis; to enable this, further synthetic tools and methodologies are needed. To this end, we have explored the first Sonogashira cross-coupling to halotryptophans in water. Broad reaction scope is demonstrated and we have explored the limits of the scope of the reaction. We have demonstrated this methodology to work excellently in the modification of model tripeptides. Furthermore, through precursor directed biosynthesis, we have generated for the first time a new to nature brominated natural product bromo-cystargamide, and demonstrated the applicability of our reaction conditions to modify this novel metabolite.Publisher PDFPeer reviewe