Formal Asymmetric Cycloaddition of Activated α,β-Unsaturated Ketones with α-Diazomethylphosphonate Mediated by a Chiral Silver SPINOL Phosphate Catalyst
nonspiro-phosphonylpyrazolines via an asymmetric formal 1,3-dipolar cycloaddition reaction of α-diazomethylphosphonate with activated, acyclic α,β-unsaturatedketones, bearing an additional nitrile electron-withdrawing group, has been developed, utilizing an in situ generated chiral silver phosphate catalyst, affording excellent stereoselectivities (up to 98% ee, 99:1 dr) and yields (up to 95%). A stepwise
Highly Efficient and Stable Blue
<scp>OLEDs</scp>
Based on B—N Bonds Embedded 6,
<scp>12‐Diphenyl</scp>
‐5,11‐dihydroindolo[3,2‐
<i>b</i>
]carbazole with Narrowband Emission and Extended Lifetime
<sup>†</sup>
12-diphenyl-5,11-dihydroindolo[3,2-b]carbazole derivatives (tPh[BN] and Cz[BN]) containing two B—N covalent bonds are easily constructed through amine-directed double borylation strategy. Both emitters behaved bright blue emission with full-width-at-half-maximum (FWHM) of 20—27 nm in solution, high fluorescence quantum efficiency over 90%, and excellent stability toward moisture. By employing triplet-triplet
Disclosed are electroluminescent devices that comprise organic layers that contain certain 2H-benzotriazole compounds. The 2H-benzotriazole compounds of blue-emitting, durable, organo-electrouminescent layers. The electroluminescent devices may be employed for full color display panels in for example mobile phones, televisions and personal computer screens.