Access to Air-Stable 1,3-Diphosphacyclobutane-2,4-diyls by an Arylation Reaction with Arynes

• Published in: Angewandte Chemie International Edition Vol. 55; no. 26; pp. 7525 - 7529
• Main Authors: Ueta, Yasuhiro, Mikami, Koichi, Ito, Shigekazu
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 20.06.2016; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Aromatic compounds; arynes; Chemistry; Chemistry, Multidisciplinary; Detectors; Fluorides; fluorine; heterocycles; Hydrogen; Hydrogen fluoride; P-type semiconductors; phosphorus; Photoabsorption; Physical Sciences; Physicochemical properties; radicals; Science & Technology; Semiconductivity; Tuning; arynes; BENZYNES; radicals; heterocycles; PHOSPHINES; INDOLYNE; GENERATION; fluorine; phosphorus
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201601907

Tuning of the physicochemical properties of the 1,3‐diphosphacyclobutane‐2,4‐diyl unit is attractive in view of materials applications. The use of arynes is shown to be effective for installing relatively electron rich aryl substituents into the open‐shell singlet P‐heterocyclic system. Treatment of the sterically encumbered 1,3‐diphosphacyclobuten‐4‐yl anion with ortho‐silylated aryl triflates in the presence of fluoride under appropriate conditions afforded the corresponding 1‐aryl 1,3‐diphosphacyclobutane‐2,4‐diyls. The air‐stable open‐shell singlet P‐heterocycles exhibit considerable electron‐donating character, and the aromatic substituent influences the open‐shell character, which is thought to be related to the property of p‐type semiconductivity. The P‐arylated 1,3‐diphosphacyclobutane‐2,4‐diyl systems can be further utilized as detectors of hydrogen fluoride (HF), which causes a remarkable change in their photoabsorption properties. A P2romising C2onstellation: The reaction of a sterically encumbered 1,3‐diphosphacyclobuten‐4‐yl anion with ortho‐silylated aryl triflates in the presence of fluoride under appropriate conditions afforded the corresponding 1‐aryl‐1,3‐diphosphacyclobutane‐2,4‐diyls (see scheme). These air‐stable open‐shell singlet P‐heterocycles exhibit considerable electron‐donating character and can be used as detectors of hydrogen fluoride.