Synthesis and reactivity of boron difluoride complexes of N,N-dimethylsalicylacetamide

Reaction of Phosgeniminium Salts with Enolates Derived from Lewis Acid Complexes of 2‘-Hydroxypropiophenones and Related β-Diketones

“…Our desire to improve the overall efficiency of this process and expand its applicability to related ring systems (eg 7 ) prompted us to examine modifications to this sequence. Having previously explored the unraveling of complex 3 to aminochromone 4 , we chose to focus on the events surrounding the formation and reaction of the boron difluoride complex 2 . Presumably, heating the mixture of 2 with phosgene iminium chloride at 80 °C allows for the generation of significant equilibrium concentrations of the corresponding enol form of 2 that is continuously siphoned off as the reaction proceeds.…”

Boron Difluoride Complex Dyes: Synthesis and Photophysical Properties

“…This alteration in the dye construction also led to considerably amplified resistance to hydrolysis [48]. 2-Aminochromones was also prepared by reacting phosgene iminium salts with 2'-hydroxyacetophenone-BF 2 complexes to afford β-chlorovinylogous amide BF 2 complex derivatives [49]. BF 2 complexes based on perylene and tetracene ( Figure 11) ligands were prepared as novel category of electron deficient arenes with long wavelength absorption and better electron affinity because of the quadrupolar structures corresponding to the resonance contributors.…”

Ethyl (O–B)-5-(difluoroboryloxy)tricyclo[4.3.1.13,8]undecane-4-carboxylate

“…The exocyclic ethoxy group may account for the asymmetry of the CÐC, CÐO and OÐB bond pairs. Presumably for similar reasons, in the majority of the 14 structures containing diuorodioxoborane rings that are archived in the Cambridge Structural Database (release of April 2003; Allen, 2002); namely CAMLUX10 (Jones et al, 1990), CUQWEQ (Balasubramanian et al, 2000), FIZGAW (Boeyens et al, 1987), HAHHUT (Morris et al, 1993), HATTAX (Stomberg et al, 1994), KONWOZ (Stomberg & Lindquist, 1991), LIYHEG (Go È rlitz et al, 1999), MIXXEW (Schiemenz & Na È ther, 2002) and NOLDOH (Dromzee et al, 1997), the pairs of bond lengths also display differences. In contrast, in ®ve structures these differences are within experimental error.…”