Cross‐coupling reactions in water using ionic liquid‐based palladium(II)–phosphinite complexes as outstanding catalysts. (29th September 2014)

• Record Type: Journal Article
• Authors: Meriç, Nermin; Aydemir, Murat; Işik, Uğur; Ocak, Yusuf Selim; Rafikova, Khadichakhan; Paşa, Salih; Kayan, Cezmi; Durap, Feyyaz; Zazybin, Alexey; Temel, Hamdi
• Is Part Of: Applied organometallic chemistry. Volume 28:Number 11(2014:Nov.)
• Page Start: 818
• Page End: 825
• Publication Date: 2014-09-29
• Subjects: Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.3205
• Languages: English
• ISSNs: 0268-2605

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Two new phosphinite ligands based on <named-content content-type="chemicalTechnology" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">ionic liquids</named-content> [(Ph<sub>2</sub>PO)C<sub>7</sub>H<sub>14</sub>N<sub>2</sub>Cl]Cl (<bold>1</bold>) and [(Cy<sub>2</sub>PO)C<sub>7</sub>H<sub>14</sub>N<sub>2</sub>Cl]Cl (<bold>2</bold>) were synthesized by reaction of 1‐(3‐chloro‐2‐hydoxypropyl)‐3‐methylimidazolium chloride, [C<sub>7</sub>H<sub>15</sub>N<sub>2</sub>OCl]Cl, with one equivalent of chlorodiphenylphosphine or chlorodicyclohexylphosphine, respectively, in anhydrous CH<sub>2</sub>Cl<sub>2</sub> and under argon atmosphere. The reactions of <bold>1</bold> and <bold>2</bold> with MCl<sub>2</sub>(cod) (M = Pd, Pt; cod = 1, 5‐cyclooctadiene) yield complexes <italic>cis</italic>‐[M([(Ph<sub>2</sub>PO)C<sub>7</sub>H<sub>14</sub>N<sub>2</sub>Cl]Cl)<sub>2</sub>Cl<sub>2</sub>] and <italic>cis</italic>‐[M(Cy<sub>2</sub>PO)C<sub>7</sub>H<sub>14</sub>N<sub>2</sub>Cl]Cl)<sub>2</sub>Cl<sub>2</sub>], respectively. All complexes were isolated as analytically pure substances and characterized using multi‐nuclear NMR and infrared spectroscopies and elemental analysis. The <named-content content-type="chemicalTechnology" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">catalytic activity</named-content> of palladium complexes based on ionic liquid phosphinite ligands <bold>1</bold> and <bold>2</bold> was investigated in <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">Suzuki cross‐coupling</named-content>. They show outstanding <named-content content-type="chemicalTechnology" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">catalytic activity</named-content> in coupling of a series of aryl bromides or aryl iodides with phenylboronic acid under the optimized reaction conditions in water. The complexes provide turnover frequencies of 57 600 and 232 800 h<sup>−1</sup> in Suzuki <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">coupling reactions</named-content> of phenylboronic acid with <italic>p</italic>‐bromoacetophenone or <italic>p</italic>‐iodoacetophenone, respectively, which are the highest values ever reported among similar complexes for Suzuki <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">coupling reactions</named-content> in water as sole solvent in <named-content content-type="reactionType chemicalTechnology" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">homogeneous catalysis</named-content>. Furthermore, the palladium complexes were also found to be highly active catalysts in the <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">Heck reaction</named-content> affording <italic>trans</italic>‐stilbenes. Copyright © 2014 John Wiley & Sons, Ltd.</p> </abstract>