Synthesis of 1H-1,3-benzazaphospholes: substituent influence and mechanistical aspects

Photonic Crystal Glucose-Sensing Material for Noninvasive Monitoring of Glucose in Tear Fluid

“…Because these derivatives were attached to the hydrogel through an amide linkage, we estimated the linked derivative pK a by measuring the pK a of 4-acetamido-3-fluorophenylboronic acid, which we prepared from 4-bromo-2-fluoroaniline. We converted the amine group to its acetamido derivative by treating 4-bromo-2-fluoroaniline with acetyl chloride in dichloromethane at 0°C in the presence of triethylamine (32 ). In the second step we prepared the corresponding boronic acid derivative by trimethoxyborate lithium halide exchange followed by hydrolysis (26 ).…”

σ2P,O‐Hybrid Ligands: Synthesis of the First 4‐Hydroxy‐1,3‐benzazaphospholes by ortho‐Lithiation of m‐Amidophenyl Diethyl Phosphates

“…The crystal structure analysis of the deuteriobenzene solvate of 6 ( Figure 2) reveals a planar ring system and bond lengths and angles similar to those of 2-tert-butyl-1H-1,3-benzazaphosphole, [22] and no noticeable changes are induced by the 4-OH group. The C-4-O bond length is in the typical range for the C-O bonds of phenols.…”

“…[22] N-Basic phosphane side products were separated by extraction with dilute aqueous sulfuric acid. and hydrolytic workup.…”

“…The 1 H and 13 C nuclei of the aromatic rings of the new compounds display the expected NMR signal splittings with 3 J H,H and typical 4 J P,H (5-6 Hz) and 1 J P,C (170-180 Hz) coupling constants and chemical shifts in accordance with values estimated from those of related compounds [14,15] and substituent effects. [22] This is attributed to the +M effect of the OH group rather than to steric shielding, as the steric effects of Me, tBu, or Ph groups versus an H atom at the 2-position to the phosphorus atom are much smaller than the electronic effects of -M or +M substituents (COOH or NHPh) at the same position. [22] This is attributed to the +M effect of the OH group rather than to steric shielding, as the steric effects of Me, tBu, or Ph groups versus an H atom at the 2-position to the phosphorus atom are much smaller than the electronic effects of -M or +M substituents (COOH or NHPh) at the same position.…”

Tavs reactions ofo-halobenzaldimines with ethyl diphenylphosphinite. Synthesis and crystal structure of a bis(phosphine oxide)

“…• C [7], and, even more remarkably, the reaction of ohaloarylazobenzenes with triethylphosphite in the presence of copper(II) acetate yields the related o-diethylphosphonatoarylazobenzenes in refluxing ethanol in good yield, via the intermediate formation of copper(I)-phosphite complexes [8,9]. Following our work, and that of others, on the coordination template-assisted formation of aryl-phosphonium, -arsonium, and -stibonium salts from the metal ionpromoted reactions of tertiary phosphines, arsines, and stibines with aryl halides bearing an appropriate donor group in close proximity to the halogen [10][11][12][13][14], we were interested in studying the reactivity of such template aryl halides in the Tavs reaction with ethyl diphenylphosphinite, which might provide a new route to some interesting chelating phosphine oxide ligands with additional heterodonor centers.…”