N. Ple

Convergent synthesis of the streptonigrin alkaloid skeleton. Directed orthometalation connection to aryl-aryl cross-coupling

Abstract A convergent synthesis of 2-[2-(4-phenyl-3-pivaloylamino) pyridyl]quinolines, the streptonigrin alkaloid skeleton, is reported. The methodology involves independent elaboration of the three main building blocks by metalation and two coupling reactions catalyzed by palladium.

First Study of Syntheses and Reactivity of Grignard Compounds in the Diazine Series. Diazines. Part 27

Abstract A preparation of Grignard derivatives of diazines is described using a halogen magnesium exchange reaction. This convenient method allows the functionalization of these rings at 0°C or even room temperature.

A new route to Septorin via controlled metalations of pyrazines. Diazines XXX

Abstract The metalation of 2-chloro-3-(1-hydroxy-4-alkoxyphenylmethyl)pyrazines with LTMP in tetrahydrofuran has been studied and afforded regioselectively functionalized compounds at C6. This regioselectivity was established by application of gradient enhanced HMBC sequence for the observation of long range 1H–15N heteronuclear couplings at natural abundance and by X-ray diffraction. Associated with the regioselective metalation at C6, the transition metal catalyzed cross coupling reaction provides a new pathway to Septorin.

Study of the mechanism of the hydride transfer with a highly reactive and stereoselective NADH model

Abstract The 1 H and 13 C NMR spectra of the chiral NADH models 3 and 4 were studied both in the presence or absence of Mg 2+ ions. These two compounds have a chiral carboxamide part derived from (S)-phenylalaninol but contrary to 3 , compound 4 has the ability to free-rotate about the C 3 CO bond. Careful analysis of the spectral results and comparison with some other studies recently published in the literature allowed the following assumptions: 1-the 1,4-dihydropyridine structure is planar both in the absence or presence of magnesium ions. 2-in the case of the rigid model 3 , the CO is out of the plane of the dihydropyridine structure. 3-with Mg 2+ the chiral amino alcohol moiety adopts a quasi-cyclic conformation in the case of 4 but not in the case of 3 . The observed enantioselectivities are explained by the mean of ternary complexes between the model, Mg 2+ and the substrate.