the Pd-catalyzed P–Ccross-coupling reaction between enol phosphates and secondary phosphane–borane complexes or phosphane oxides. The reaction was performed under mild conditions, owing to Pd activation of the P–H bonds of the phosphane–boranes (or phosphane oxides) and to the powerful enol phosphate coupling reagents. New useful chiral and achiral α-β-alkenylphosphane derivatives bearing an amido
Structural analysis of N,N-diacyl-1,4-dihydropyrazine by variable-temperature NMR and DFT calculation
作者:Xiu-qing Song、Hong-bo Tan、Hong Yan、Yu Chang
DOI:10.1016/j.molstruc.2017.01.019
日期:2017.4
unambiguously confirmed by NMRspectra and high-resolution mass spectrometry. The NMRspectra of 1 showed complicated rather than conventional spectroscopy. Variable-temperature experiments and DFT calculation (PES) were used to investigate this phenomenon. DFT calculations confirmed that the structures of the two rotamers of 1 correspond to those determined by NMR in solution, and gave the syn-anti interconversion
range of readily available α-phosphateenamides were subjected to (hetero)aromatic dioxazaborocanes (DABO boronates), providing the desired α-functionalized enamides in high yields via palladium-catalyzed cross-coupling reactions. Notably, the reaction proceeds in the presence of a slight excess of boron derivatives and tolerates cyclic, nonaromatic and/or electron-rich enamides.