Effect of the Phosphine Steric and Electronic Profile on the Rh-promoted Dehydrocoupling of Phosphine-boranes

Overview

Journal Inorg Chem

Specialty Chemistry

Date 2014 Mar 13

PMID 24617924

Citations 5

Authors

Thomas N Hooper

Miguel A Huertos

Titel Jurca

Sebastian D Pike

Andrew S Weller

Ian Manners

Affiliations

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Abstract

The electronic and steric effects in the stoichiometric dehydrocoupling of secondary and primary phosphine-boranes H3B·PR2H [R = 3,5-(CF3)2C6H3; p-(CF3)C6H4; p-(OMe)C6H4; adamantyl, Ad] and H3B·PCyH2 to form the metal-bound linear diboraphosphines H3B·PR2BH2·PR2H and H3B·PRHBH2·PRH2, respectively, are reported. Reaction of [Rh(L)(η(6)-FC6H5)][BAr(F)4] [L = Ph2P(CH2)3PPh2, Ar(F) = 3,5-(CF3)2C6H3] with 2 equiv of H3B·PR2H affords [Rh(L)(H)(σ,η-PR2BH3)(η(1)-H3B·PR2H)][BAr(F)4]. These complexes undergo dehydrocoupling to give the diboraphosphine complexes [Rh(L)(H)(σ,η(2)-PR2·BH2PR2·BH3)][BAr(F)4]. With electron-withdrawing groups on the phosphine-borane there is the parallel formation of the products of B-P cleavage, [Rh(L)(PR2H)2][BAr(F)4], while with electron-donating groups no parallel product is formed. For the bulky, electron rich, H3B·P(Ad)2H no dehydrocoupling is observed, but an intermediate Rh(I) σ phosphine-borane complex is formed, [Rh(L){η(2)-H3B·P(Ad)2H}][BAr(F)4], that undergoes B-P bond cleavage to give [Rh(L){η(1)-H3B·P(Ad)2H}{P(Ad)2H}][BAr(F)4]. The relative rates of dehydrocoupling of H3B·PR2H (R = aryl) show that increasingly electron-withdrawing substituents result in faster dehydrocoupling, but also suffer from the formation of the parallel product resulting from P-B bond cleavage. H3B·PCyH2 undergoes a similar dehydrocoupling process, and gives a mixture of stereoisomers of the resulting metal-bound diboraphosphine that arise from activation of the prochiral P-H bonds, with one stereoisomer favored. This diastereomeric mixture may also be biased by use of a chiral phosphine ligand. The selectivity and efficiencies of resulting catalytic dehydrocoupling processes are also briefly discussed.

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References

Dietrich B, Goldberg K, Heinekey D, Autrey T, Linehan J . Iridium-catalyzed dehydrogenation of substituted amine boranes: kinetics, thermodynamics, and implications for hydrogen storage. Inorg Chem. 2008; 47(19):8583-5. DOI: 10.1021/ic801161g. View

Jaska C, Dorn H, Lough A, Manners I . Chemistry of phosphine-borane adducts at platinum centers: synthesis and reactivity of PtII complexes with phosphinoborane ligands. Chemistry. 2002; 9(1):271-81. DOI: 10.1002/chem.200390020. View

Thoms C, Marquardt C, Timoshkin A, Bodensteiner M, Scheer M . The oligomerization of phosphinoborane by titanium complexes. Angew Chem Int Ed Engl. 2013; 52(19):5150-4. DOI: 10.1002/anie.201209703. View

Huertos M, Weller A . Intermediates in the Rh-catalysed dehydrocoupling of phosphine-borane. Chem Commun (Camb). 2012; 48(57):7185-7. DOI: 10.1039/c2cc32696e. View

Dorn , Singh , Massey , Lough , Manners I . Rhodium-Catalyzed Formation of Phosphorus-Boron Bonds: Synthesis of the First High Molecular Weight Poly(phosphinoborane). Angew Chem Int Ed Engl. 1999; 38(22):3321-3323. DOI: 10.1002/(sici)1521-3773(19991115)38:22<3321::aid-anie3321>3.0.co;2-0. View

Clark T, Rodezno J, Clendenning S, Aouba S, Brodersen P, Lough A . Rhodium-catalyzed dehydrocoupling of fluorinated phosphine-borane adducts: synthesis, characterization, and properties of cyclic and polymeric phosphinoboranes with electron-withdrawing substituents at phosphorus. Chemistry. 2005; 11(15):4526-34. DOI: 10.1002/chem.200401296. View

Hamilton C, Baker R, Staubitz A, Manners I . B-N compounds for chemical hydrogen storage. Chem Soc Rev. 2008; 38(1):279-93. DOI: 10.1039/b800312m. View

Robertson A, Leitao E, Jurca T, Haddow M, Helten H, Lloyd-Jones G . Mechanisms of the thermal and catalytic redistributions, oligomerizations, and polymerizations of linear diborazanes. J Am Chem Soc. 2013; 135(34):12670-83. DOI: 10.1021/ja404247r. View

Leitao E, Jurca T, Manners I . Catalysis in service of main group chemistry offers a versatile approach to p-block molecules and materials. Nat Chem. 2013; 5(10):817-29. DOI: 10.1038/nchem.1749. View

10.

Dallanegra R, Robertson A, Chaplin A, Manners I, Weller A . Tuning the [L2Rh···H3B·NR3]+ interaction using phosphine bite angle. Demonstration by the catalytic formation of polyaminoboranes. Chem Commun (Camb). 2011; 47(13):3763-5. DOI: 10.1039/c0cc05460g. View

11.

Forster T, Tuononen H, Parvez M, Roesler R . Characterization of beta-B-agostic isomers in zirconocene amidoborane complexes. J Am Chem Soc. 2009; 131(19):6689-91. DOI: 10.1021/ja901460y. View

12.

Staubitz A, Sloan M, Robertson A, Friedrich A, Schneider S, Gates P . Catalytic dehydrocoupling/dehydrogenation of N-methylamine-borane and ammonia-borane: synthesis and characterization of high molecular weight polyaminoboranes. J Am Chem Soc. 2010; 132(38):13332-45. DOI: 10.1021/ja104607y. View

13.

Zapf A, Beller M . The development of efficient catalysts for palladium-catalyzed coupling reactions of aryl halides. Chem Commun (Camb). 2005; (4):431-40. DOI: 10.1039/b410937f. View

14.

Friedrich A, Drees M, Schneider S . Ruthenium-catalyzed dimethylamineborane dehydrogenation: stepwise metal-centered dehydrocyclization. Chemistry. 2009; 15(40):10339-42. DOI: 10.1002/chem.200901372. View

15.

Shuttleworth T, Huertos M, Pernik I, Young R, Weller A . Bis(phosphine)boronium salts. Synthesis, structures and coordination chemistry. Dalton Trans. 2013; 42(36):12917-25. DOI: 10.1039/c3dt50817j. View

16.

Spielmann J, Piesik D, Harder S . Thermal decomposition of mono- and bimetallic magnesium amidoborane complexes. Chemistry. 2010; 16(28):8307-18. DOI: 10.1002/chem.201000028. View

17.

Johnson H, Robertson A, Chaplin A, Sewell L, Thompson A, Haddow M . Catching the first oligomerization event in the catalytic formation of polyaminoboranes: H3B·NMeHBH2·NMeH2 bound to iridium. J Am Chem Soc. 2011; 133(29):11076-9. DOI: 10.1021/ja2040738. View

18.

Lee K, Clark T, Lough A, Manners I . Synthesis and dehydrocoupling reactivity of iron and ruthenium phosphine-borane complexes. Dalton Trans. 2008; (20):2732-40. DOI: 10.1039/b718918d. View

19.

Waterman R . Mechanisms of metal-catalyzed dehydrocoupling reactions. Chem Soc Rev. 2013; 42(13):5629-41. DOI: 10.1039/c3cs60082c. View

20.

Ledger A, Ellul C, Mahon M, Williams J, Whittlesey M . Ruthenium bidentate phosphine complexes for the coordination and catalytic dehydrogenation of amine- and phosphine-boranes. Chemistry. 2011; 17(31):8704-13. DOI: 10.1002/chem.201100101. View