2021, Fischer, Malte, Hering-Junghans, Christian

1,3-Phosphaazaallenes are heteroallenes of the type RP-C-NR′ and little is known about their reactivity. In here we describe the straightforward synthesis of ArPCNR (Ar = Mes*, 2,4,6-tBu-C6H2;MesTer, 2.6-(2,4,6-Me3C6H2)-C6H3;DipTer, 2.6-(2,6-iPr2C6H2)-C6H3; R =tBu; Xyl, 2,6-Me2C6H3) starting from phospha-Wittig reagents ArPPMe3and isonitriles CNR. It is further shown that ArPCNtBu are thermally labile with respect to the loss of iso-butene and it is shown that the cyanophosphines ArP(H)CN are synthetically feasible and form the corresponding phosphanitrilium borates with B(C6F5)3, whereas deprotonation ofDipTerP(H)CN was shown to give an isolable cyanidophosphide. Lastly, the reactivity of ArPCNR towards Pier's borane was investigated, showing hydroboration of the C-N bond in Mes*PCNtBu to give a hetero-butadiene, while withDipTerPCNXyl the formation of the Lewis acid-base adduct with a B-P linkage was observed. © The Royal Society of Chemistry 2021.

2019, Wozniak, Bartosz, Tin, Sergey, de Vries, Johannes G.

The limits to the supply of fossil resources and their ever increasing use forces us to think about future scenarios for fuels and chemicals. The platform chemical 5-hydroxymethyl-furfural (HMF) can be obtained from biomass in good yield and has the potential to be converted in just a few steps into a multitude of interesting products. Over the last 20 years, the conversion of HMF to 1-hydroxyhexane-2,5-dione (HHD) has been studied by several groups. It is possible to convert HMF into HHD by hydrogenation/hydrolytic ring opening reaction in aqueous phase using various heterogeneous and homogeneous catalysts. This review addresses both the state of the art of HHD synthesis, including mechanistic aspects of its formation, as well as the recent progress in the application of HHD as a building block for many useful chemicals including pyrroles, cyclopentanone derivatives and triols. © 2019 The Royal Society of Chemistry.