Oxidative addition of BrCtCC(dO)NR 2 to [Pd(PPh 3) 4 ] affords the trans-alkynylbromopalladium complexes trans-[Br(PPh 3) 2 Pd-CtCC(dO)NR 2 ] (NR 2) NMe 2 (2a), N(CH 2) 4) (2b)). Subsequent reaction of 2a,b with P i Pr 3 in excess gives trans-[Br(P i Pr 3) 2 Pd-CtCC(dO)NR 2 ] (5a,b). The analogous reaction of 2b with P(C 6 H 4 OMe-4) 3 gives trans-[Br(P{C 6 H 4 OMe-4} 3) 2 Pd-CtCC(dO)NR 2 ] (7b), and that of 2a with trifluoroacetate gives trans-[(F 3 CCOO)(PPh 3) 2 Pd-CtCC(dO)NMe 2 ] (9a). Methylation of 2a,b, 7b, and 9a with either MeOTf or [Me 3 O]BF 4 and ethylation of 2a,b with [Et 3 O]BF 4 yield the first cationic allenylidene complexes of palladium, trans-[R*(PR′ 3) 2 Pd-CtCC(OMe)NR 2 ] + X-(R*) Br, CF 3 COO; R′) Ph, C 6 H 4 OMe-4, i Pr; X) OTf, BF 4).
The invention of electrospinning has solved the problem of producing micro-and nanoscaled metal oxide fibres in bulk quantities. However, until now no methods have been available for preparing a single nanofibre of a metal oxide. In this work, the direct drawing method was successfully applied to produce metal oxide (SnO 2 , TiO 2 , ZrO 2 , HfO 2 and CeO 2 ) fibres with a high aspect ratio (up to 10 000) and a diameter as small as 200 nm. The sol-gel processing includes consumption of precursors obtained from alkoxides by aqueous or non-aqueous polymerization. Shear thinning of the precursors enables pulling a material into a fibre. This rheological behaviour can be explained by sliding of particles owing to external forces. Transmission (propagation) of light along microscaled fibres and their excellent surface morphology suggest that metal oxide nanofibres can be directly drawn from sol precursors for use in integrated photonic systems.
In this work different strategies for synthesis of allyl hydrazine were investigated and compared in terms of selectivity, reproducibility and yield. The motivation of this study was mainly the low selectivity and reproducibility of the classical synthetic route, which utilizes allyl halide and hydrazine hydrate as parent substances. In search of more effective methods we have tested the potential of protecting group strategy by exploiting different Boc-hydrazines. We conclude that the approach overcomes the shortcomings of the classical method, as the aforementioned essential synthesis characteristics can be considerably improved. The best results were obtained by employing the route starting with tri-Boc-hydrazine.
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