Two isomers of a bis(diphenylphosphino)phosphinine, and the synthesis and reactivity of Ru arene/Cp* phosphinophosphinine complexes12. (14th November 2018)

• Record Type: Journal Article
• Authors: Newland, Robert J.; Delve, Matthew P.; Wingad, Richard L.; Mansell, Stephen M.
• Is Part Of: New journal of chemistry. Volume 42:Number 24(2018)
• Page Start: 19625
• Page End: 19636
• Publication Date: 2018-11-14
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c8nj03632b
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Two isomers of a bis(diphenylphosphino)phosphinine have been synthesised, and the Ru coordination chemistry of a 2-phosphinophosphinine extended to include reactions of H2 O across a PC double bond. Abstract : The reaction of 4, 6-di( tert -butyl)-1, 3, 2-diazaphosphinine (3 ) with two equivalents of MeCCPPh2 gave two isomeric products, 2, 6-bis(diphenylphosphino)-3, 5-dimethylphosphinine (5 ) and 2, 5-bis(diphenylphosphino)-3, 6-dimethylphosphinine (6 ), which were successfully separated and their molecular structures determined by X-ray crystallography. Although the 2, 6-bis(iminophosphorano)phosphinine7 was readily synthesised from5 using mesityl azide, its coordination to late transition metals was not achieved. The reaction of 2-diphenylphosphino-3-methyl-6-trimethylsilylphosphinine (1 ) with [{Ru(Cl)(μ-Cl)( p -cymene)}2 ] generated two products: cis -[Ru(Cl)2 (1 )2 ] (2 ) and the dinuclear species [Ru(μ-Cl)3 ( p -cymene)Ru(Cl)(1 )] (8 ), which was characterised by single crystal X-ray diffraction. The reaction of1 with [{Ru(Cl)(μ-Cl)(C6 Me6 )}2 ]/NH4 PF6 led to cleavage of the SiMe3 group and addition of H2 O across a PC bond to generate [Ru(C6 Me6 )(1-OH-2-PPh2 -3-MePC5 H4 )][PF6 ] (9 ). The reaction of1 with [{Ru(Cp*)(μ3 -Cl)}4 ] yielded [Ru(Cp*)(Cl)(1 )] (10 ) which readily reacted with H2 O across a PC bond to form [Ru(Cp*)(Cl)(1-OH-2-PPh2 -3-Me-6-SiMe3 PC5 H3 )] (11 ). Neither9, 10, 11 or cis -[Ru(Cl)2 (dppm)2 ] were effective precatalysts for the transfer hydrogenation (TH) of acetophenone, unlike2 which in addition was also found to catalyse the TH of benzophenone at 82 °C (0.1 mol%2 with 0.5 mol% KO t Bu in i PrOH), with much lower activity for 2-fluorobenzaldehyde and 4-methylcyclohexanone.11 was a competent precatalyst for the hydrogen-borrowing upgrading of EtOH/MeOH to isobutanol, albeit in lower yields compared to2 .