Nucleophilic borohydride: selective reductive displacement of halides, sulfonate esters, tertiary amines, and N,N-disulfonimides with borohydride reagents in polar aprotic solvents

Abstract

In Tabellen werden unter Auswertung von zahlreichen Lit.‐ Stellen nucleophile Substitutionsreaktionen mit Boranat beschrieben, die z.B. zur Umwandlung von Halogeniden oder Sulfonaten (I) in Kohlenwasserstoffe, zur Eliminierung einer Methylgruppe aus den aus (IV) hergestellten Ammonium‐Verbindungen (V) zu den tert. Aminen (VI) oder auch zu einer Spaltung von Disulfonylimiden (VII) unter Bildung der Kohlenwasserstoffe (VIII) führen können.

Sex pheromone of the oleander scale, Aspidiotus nerii : Structural characterization and absolute configuration of an unusual functionalized cyclobutane

“…However, biological activity was recovered through ''reacetylation,'' and the regenerated compound was found identical (GLC, MS) to the natural pheromone. The alcohol also was derivatized according to two different sequences to obtain more structural information: hydrogenolysis by the Pt(Al 2 O 3 )͞lithium aluminum hydride system (12) and bromination of the hydrogenated alcohol followed by sodium borohydride reduction in DMSO (13). The first process gave ca.…”

“…This unusual amount of pheromone available allowed us to record 1 H (600 MHz) (Fig. 2b) and 13 C NMR (100.5 MHz) spectra as well as two-dimensional 1 HO 1 H COSY (600 MHz) and 1 HO 13 C heteronuclear correlations (reverse mode, 400 MHz) in C 6 D 6 . Resonances were observed for 28 protons including 3 methyl groups and 17 carbon atoms.…”

“…Resonances were observed for 28 protons including 3 methyl groups and 17 carbon atoms. The 13 C spectrum showed resonances for three methyl groups, nine methylene carbons (two olefinic ones), four quaternary carbons (only one in the aliphatic region), and one methine carbon. Because of the extensive signal overlapping in the aliphatic region, the 1 H NMR spectrum first had to be analyzed through the 1 HO 13 C correlations, which allowed the determination of the J 2 connectivities as shown in Table 1.…”

“…Mass spectrometry was carried out on a Nermag (Quad Service, Poissy, France) R-10Ϫ10 C gas chromatograph-mass spectrometer (GC-MS) or a R-30-10 triple quadrupole (MS-MS analyzer) instrument under computer control and the following electron impact (EI) source conditions: electron energy, 70 eV; filament current, 150 A; temperature, 200°C. Chemical ionization (CI) was performed at 95 eV electron energy and 130°C source temperature by using NH 3 13 C signal at ␦ 128.7 ppm in 13 C NMR spectra). Microderivatization.…”

“…We report herein studies directed on the identification of the sex pheromone of the oleander scale by GC-MS, low-energy MS-MS, 1 H NMR, microchemical reactions, and, finally, by high-resolution two-dimensional 1 H-1 H and 1 H- 13 C NMR correlations. The proposed structure, a sesquiterpenic functionalized cyclobutane acetate, has been confirmed-including its absolute configuration-by synthesis and biological activity in greenhouse bioassays and field tests.…”