Wasserstoffbrückenbindungen in Lösungen ortho‐phosphorylsubstituierter Phenole

Abstract

ortho‐P(O)‐substituierte Phenole 4 sind im Gegensatz zu offenkettigen Phosphoryl‐enolen 1 durch Spaltung der Phenol‐alkyl‐äther gut zugänglich und als Studienobjekte für die gegenseitige Beeinflussung der P  O‐ und der OH‐Gruppe in 1.2‐Position einer CC‐Doppelbindung geeignet. Rf(DC)‐Werte deuten darauf hin, daß die Phenole 4 in Lösung bei ausreichender Basizität des Phosphoryl‐O‐Atoms Wasserstoffbrückenbindungen PO ⃛ H–O ausbilden, während stark elektronenziehende P‐Substituenten die Beteiligung der PO‐Gruppe unwahrscheinlich machen. δOH‐ und Pka‐Werte zeigen, daß in Dimethylsulfoxid nur im ersten Fall (Phosphinoxide 4a–g) PO ⃛ HO‐Brücken existieren, während bei Phosphonsäure‐arylestern 4i–k Addukte mit DMSO‐Molekülen gebildet werden. Für diese Differenzierung sind in erster Linie induktive Substituenten‐effekte verantwortlich. Die UV‐Spektren deuten lediglich einen geringen konjugativen Beitrag von P‐Phenylsubstituenten an.

Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide by Using Bifunctional One‐Component Phosphorus‐Based Organocatalysts

“…Product 3k (2.76 g, 5.09 mmol, > 99 %) was obtained as ac olorless oil. 1 HNMR (300 MHz, CDCl 3 ): d = 0.89 (t, 3 J(H,H) = 6.7 Hz, 9H), 1.26-1.36 (m, 24 H), 1.43-1.64 (m, 12 H), 2.29-2.39 (m, 6H), 2.72 (dt, 3 (2-Hydroxyphenyl)(methyl)diphenylphosphonium iodide (6 a) [52] In accordance with GP1, as uspension of 4a (278 mg, 1.00 mmol) and 5 (147 mg, 1.04 mmol) in diethyl ether (10 mL) was stirred 16 ha t2 3 8C. The product was filtered and washed with diethyl ether (2 5 mL) to give 6a (402 mg, 0.957 mmol, 96 %) as ac olorless solid.…”

Intra- and Intermolecular Hydrogen Bonding in 2-Phosphinylphenol: A Quantum Chemical Study

“…Dimer. Since experimental results on 2-diphenylphosphinylphenol and related molecules indicate that in the solid state and in solution there are intermolecular hydrogen bonds, ,, we thought it important to check the stability of the dimeric form of 2-phosphinylphenol. The geometry found is shown in Figure together with its parameters from an HF/6-31G* level calculation.…”

o‐Hydroxyarylphosphanes: Strategies for Syntheses of Configurationally Stable, Electronically and Sterically Tunable Ambiphiles with Multiple Applications

“…2-Diphenylphosphanylphenol and 2-di-(adamantyl)phosphanylphenol 1 (R=Ph, 1-Ada, R n = H), [34,35] were prepared similarly by reaction of o-anisyl-MgBr with ClPPh 2 and ClPAda 2 (2 mol % CuCl), followed by subsequent deprotection with HI/H 3 PO 2 [34] and BBr 3 /Et 3 N/MeOH, [35] respectively. The method is also applicable to 2,5-diphosphanylhydroquinones, demonstrated for 4 (R=Ph) by conversion of ClPPh 2 with the Grignard solution formed from 2,5-dibromo-1,4-dimethoxybenzene or with 2,5-Li 2 C 6 H 2 (OMe) 2 and final demethylation with AlCl 3 [36] [37] A multistep synthesis of optically active (R)-and (S)-o-phosphanylphenol derivatives using a chiral auxiliary and diastereoisomer separation is depicted in Scheme 1c.…”

“…The first o ‐phosphanylphenol was obviously P(C 6 H 4 OH) 3 hydrate ( 3 , R n =H), like its p ‐isomer obtained in 1961 by Neunhoefer and Lamza [33] by reaction of anisyl‐MgBr and PCl 3 , subsequent demethylation of the respective tris(anisyl)phosphane by heating (2‐3 h/100 °C) with aqueous HI (57 %) in the presence of H 3 PO 2 and neutralization of the hydroiodide (NaOH/CO 2 ) Scheme 1a. 2‐Diphenylphosphanylphenol and 2‐di(adamantyl)phosphanylphenol 1 (R=Ph, 1‐Ada, R n =H), [34,35] were prepared similarly by reaction of o ‐anisyl‐MgBr with ClPPh 2 and ClPAda 2 (2 mol % CuCl), followed by subsequent deprotection with HI/H 3 PO 2 [34] and BBr 3 /Et 3 N/MeOH, [35] respectively. The method is also applicable to 2,5‐diphosphanylhydroquinones, demonstrated for 4 (R=Ph) by conversion of ClPPh 2 with the Grignard solution formed from 2,5‐dibromo‐1,4‐dimethoxybenzene or with 2,5‐Li 2 C 6 H 2 (OMe) 2 and final demethylation with AlCl 3 [36] (Scheme 1b).…”