Borane reaction chemistry. Alkyne insertion reactions into boron-containing clusters. Products from the thermolysis of [6,9-(2-HC[triple bond]C-C5H4N)2-arachno-B10H12].

The stirring of [ortho-(HC[triple bond]C)-C(5)H(4)N] with [nido-B(10)H(14)] in benzene affords [6,9-{ortho-(HC[triple bond]C)-C(5)H(4)N}(2)-arachno-B(10)H(12)] 1 in 93% yield. In the solid state, 1 has an extended complex three-dimensional structure involving intramolecular dihydrogen bonding, which accounts for its low solubility. Thermolysis of 1 gives the known [1-(ortho-C(5)H(4)N)-1,2-closo-C(2)B(10)H(11)] 2 (13%), together with new [micro-5(N),6(C)-(NC(5)H(4)-ortho-CH(2))-nido-6-CB(9)H(10)] 3 (0.4%), [micro-7(C),8(N)-(NC(5)H(4)-ortho-CH(2))-nido-7-CB(10)H(11)] (0.4%) , 4 binuclear [endo-6'-(closo-1,2-C(2)B(10)H(10))-micro-(1(C),exo-6'(N))-(ortho-C(5)H(4)N)-micro-(exo-8'(C),exo-9'(N))-(ortho-(CH(2)CH(2))-C(5)H(4)N)-arachno-B(10)H(10)] (0.5%) 5, and [exo-6(C)-endo-6(N)-(ortho-(CH[double bond]CH)-C(5)H(4)N)-exo-9(N)-(ortho-(HC[triple bond]C)-C(5)H(4)N)-arachno-B(10)H(11)] 6. An improved solvent-free route to 2 is also presented. This set of compounds features an increasing cluster incorporation of the ethynyl moiety, initially by an effective internal hydroboration, affording an arachno to nido and then a nido to arachno:closo sequence of cluster geometry. An alternative low-temperature route to internal hydroboration is demonstrated in the room temperature reaction of [closo-B(11)H(11)][N(n)Bu(4)](2) with CF(3)COOH and [ortho-(HC[triple bond]C)-C(5)H(4)N], which gives [micro-1(C),2(B)-[ortho-C(5)H(4)N-CH(2)]-closo-1-CB(11)H(10)] 7 (40%) in which one carbon atom is incorporated into the cluster; a similar reaction with [ortho-(N[triple bond]C)-C(5)H(4)N] affords [N(n)Bu(4)][7-(ortho-N[triple bond]C-C(5)H(4)N)-nido-B(11)H(12)], 8 (68%) and stirring [ortho-(N[triple bond]C)-C(5)H(4)N] with [nido-B(10)H(14)] quantitatively affords the cyano analogue of 1, [6,9-{ortho-(N[triple bond]C)-C(5)H(4)N}(2)-arachno-B(10)H(12)] 9. All compounds were characterised by single-crystal X-ray diffraction analysis and NMR spectroscopy.

[1]  Z. Otwinowski,et al.  [20] Processing of X-ray diffraction data collected in oscillation mode. , 1997, Methods in enzymology.

[2]  J. Kennedy,et al.  Polyhedral ruthenaborane chemistry. Approaches to encapsulated boron cores. The isolation and characterisation of the partially encapsulated isocloso 10-vertex {RuB9} cluster compound [(PPh3)RuB9H9{RuCl2(PPh3)2}2] , 2005 .

[3]  F. Teixidor,et al.  Rhodium Complexes with the New Anionic Diphosphine [7,8-(PPh2)2-7,8-C2B9H10]- Ligand , 1996 .

[4]  F. Teixidor,et al.  A Route to exo-Heterodisubstituted and Monosubstituted o-Carborane Derivatives. , 1997, Inorganic chemistry.

[5]  J. Kennedy,et al.  Ten-vertex metallaborane chemistry. Aspects of the iridadecaborane closo→isonido→isocloso structural continuum , 1992 .

[6]  J. Kennedy,et al.  Identification of the endo,exo isomer of 6,9-(PMe2Ph)2-arachno-B10H12 by nuclear magnetic resonance spectroscopy , 1987 .

[7]  Robin Taylor,et al.  New software for searching the Cambridge Structural Database and visualizing crystal structures. , 2002, Acta crystallographica. Section B, Structural science.

[8]  T. Jelínek,et al.  Eleven-vertex polyhedral dicarbaplatinaborane chemistry-aspects of the chemistry of some closo-structured {1,2,3-PtC2B8} species and some related compounds , 1993 .

[9]  L. Sneddon,et al.  Reactions of decaborane(14) with silylated acetylenes. Synthesis of the new monocarbon carborane 9-Me2S-7-[(Me3Si)2CH]CB10H11 , 1987 .

[10]  Louis J. Farrugia,et al.  ORTEP-3 for Windows - a version of ORTEP-III with a Graphical User Interface (GUI) , 1997 .

[11]  J. Kennedy,et al.  Polyhedral iridaborane chemistry: Elements of the 10-vertex closo–isonido–isocloso continuum , 2006 .

[12]  D. Reed.  The role of NMR in boron chemistry , 1993 .

[13]  F. Teixidor,et al.  A novel Rh–B σ bond. Crystal structure of [N(CH3)4][RhCl{7,8-µ-S(CH2CH2)S-C2B9H10}{σ-7,8-µ-S(CH2CH2)S-C2B9H9}] , 1991 .

[14]  Leonard J. Barbour,et al.  X-Seed — A Software Tool for Supramolecular Crystallography , 2001 .

[15]  J. Michl,et al.  The Explosive “Inert” Anion CB11(CF3)12- , 2000 .

[16]  J. Ayllón,et al.  Stable silver complexes with C2B9H12-derivatives , 1994 .

[17]  J. Kennedy,et al.  Polyhedral Monocarbaborane Chemistry. A Review of Recent Developments Among C -Aryl Monocarbaborane Systems , 2002 .

[18]  F. Teixidor,et al.  Synthesis of [7,8-(PPh2)2-7,8-C2B9H10]-: a ligand analogous to 1,2-bis(diphenylphosphino)ethane with a "built-in" negative charge , 1993 .

[19]  M. A. Fox,et al.  C-arylation and C-heteroarylation of icosahedral carboranes via their copper(I) derivatives , 1993 .

[20]  J. Ayllón,et al.  A novel B–H⇀Ru agostic bond. Crystal structure of [RuCl{7,8-µ-S(CH2CH2)S-C2B9H10}(PPh3)2]·Me2CO , 1992 .

[21]  J. Ayllón,et al.  Silver coordination to exo-dithio-7,8-dicarba-nido-undecaborate derivatives. Sulfur to metal and open face to metal: two ways of bonding , 1992 .

[22]  J. Kennedy,et al.  Nine-vertex polyhedral iridamonocarbaborane chemistry. Products of thermolysis of [(CO)(PPh3)2IrCB7H8] and emerging alternative cluster-geometry patterns , 1994 .

[23]  N. N. Greenwood,et al.  Preparation, structure, and nuclear magnetic resonance properties of the nine-vertex nido-rhenaborane [(PMe2Ph)3H2ReB8H11] and some related chemistry , 1988 .

[24]  J. Kennedy,et al.  Two-dimensional 1H–1H COSY n.m.r. spectroscopy in polyhedral boron hydride chemistry , 1986 .

[25]  V. I. Bregadze,et al.  Dicarba-closo-dodecaboranes C2B10H12 and their derivatives , 1992 .

[26]  J. Kennedy,et al.  Macropolyhedral boron-containing cluster chemistry. A synthetic approach via the auto-fusion of [6,9-(SMe2)2-arachno-B10H12]. , 2006, Dalton transactions.

[27]  S. Teat,et al.  An approach to megalo-boranes. Mixed and multiple cluster fusions involving iridaborane and platinaborane cluster compounds. Crystal structure determinations by conventional and synchrotron methods , 1999 .

[28]  F. Teixidor,et al.  Radical reactions catalysed by ruthenium(II) complexes with anionic carborane phosphine ligands: Kharasch addition to olefins and controlled polymerisation , 2000 .

[29]  F. Teixidor,et al.  The “Rh(PPh3)2” and “Rh(cod)” Fragments as Probes To Compare the Coordinating and Electronic Characteristics of C−SR and C−PPh2 in Heterodisubstituted Carborane Ligands , 1998 .

[30]  J. Kennedy,et al.  Metallaheteroborane chemistry. Part 3. Synthesis of [2,2-(PR3)2-1,2-TePtB10H10](R3= Et3, Bun3, or Me2Ph), their characterisation by nuclear magnetic resonance spectroscopy, and the crystal and molecular structure of [2,2-(PEt3)2-1,2-TePtB10H10] , 1988 .

[31]  J. Kennedy,et al.  Metallaborane reaction chemistry , 1999 .

[32]  T. Jelínek,et al.  Polyhedral monocarbaborane chemistry. Some C-phenylated seven, eight, nine, ten, eleven and twelve-vertex species. , 2006, Dalton transactions.

[33]  J. Michl,et al.  Chemistry of the carba-closo-dodecaborate(-) anion, CB(11)H(12)(-). , 2006, Chemical reviews.

[34]  J. Kennedy,et al.  Isolation and Structure of [(PPh3)3(PPh2)2Pd4B20H16]. A Possible Prognostic for New Globular Borane-Based Cluster Architectures , 1999 .

[35]  W. Hutton,et al.  TWO‐DIMENSIONAL BORON‐11‐BORON‐11 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AS A PROBE OF POLYHEDRAL STRUCTURE: APPLICATION TO BORON HYDRIDES, CARBORANES, METALLABORANES, AND METALLACARBORANES , 1984 .

[36]  F. Teixidor,et al.  Nido-Carborane-Containing Compounds Resulting from the Reaction of closo-Carboranes with Transition Metal Complexes , 1994 .

[37]  S. Teat,et al.  Macropolyhedral boron-containing cluster chemistry: Models for intermediates en route to globular and discoidal megaloborane assemblies. Structures of [nido-B10H12(nido-B5H8)2] and [(CH2CH2C5H4N)-arachno-B10H10(NC5H4-closo-C2B10H10)] as determined by synchrotron X-ray diffraction analysis , 2002 .

[38]  J. Kennedy,et al.  Polyhedral azadicarbaborane chemistry. The ‘converse’ synthesis of a small family of 6,9-(NHR)-bridged-arachno-5,10-dicarbadecaboranes , 2000 .

[39]  M. Ward,et al.  Syntheses, crystal structures, and electrochemical and spectroscopic properties of ruthenium complexes of the N,S-bidentate ligand 2-(2-pyridyl)benzenethiol , 1997 .

[40]  J. Ayllón,et al.  Modulation of the B(3)-H.fwdharw.Ru Distances in 7,8-Dicarba-nido-undecaborate Derivatives , 1994 .

[41]  S. Heřmánek.  NMR as a tool for elucidation of structures and estimation of electron distribution in boranes and their derivatives , 1999 .

[42]  J. Kennedy,et al.  Steric and metal-centre control of two-, three- and four-orbital carborane-metal interaction in tin and platinum complexes of the {C2B8H9X} ligand, where X H and Ph☆ , 1992 .

[43]  J. Kennedy,et al.  Metallaborane reaction chemistry. Part 1. Two interesting closed cluster compounds from the reaction of acetylene with an open nido-6-iridadecaborane , 1993 .

[44]  N. N. Greenwood,et al.  Open cluster configurations of [1,1-(PPh3)2-1-H-1,2,4-IrC2B8H10] and other formally Wadian 24-electron 11-vertex species , 1989 .

[45]  M. A. Fox,et al.  Intra- and inter-molecular carboranyl C–H⋯N hydrogen bonds in pyridyl-containing ortho-carboranes , 2003 .

[46]  K. Wade,et al.  PREPARATION OF C-2-PYRIDYL DERIVATIVES OF ICOSAHEDRAL CARBORANES VIA COPPER(I) INTERMEDIATES , 1996 .

[47]  A. Laromaine,et al.  Synthesis, reactivity and complexation studies of N,S exo-heterodisubstituted o-carborane ligands. Carborane as a platform to produce the uncommon bidentate chelating (pyridine)N-C-C-C-s(H) motif. , 2008, Dalton transactions.

[48]  Z. Leśnikowski.  Boron Clusters − A New Entity for DNA‐Oligonucleotide Modification , 2003 .

[49]  F. Teixidor,et al.  Partial Degradation of the New exo -Heterodisubstituted Carborane Derivatives with d 10 Transition Metal Ions (Cu, Au) , 1999 .

[50]  J. Kennedy,et al.  METALLABORANE HETEROATOM INCORPORATION REACTIONS : ENYNE INSERTION INTO ARACHNO-(CO)(PME3)2HIRB8H12 , 1998 .

[51]  N. N. Greenwood,et al.  The unexpected open cluster structure of [1-(.eta.6-MeC6H4CHMe2-4)-2,4-Me2-1,2,4-RuC2B8H8] , 1987 .

[52]  G. Sheldrick.  Phase annealing in SHELX-90: direct methods for larger structures , 1990 .

[53]  T. Jelínek,et al.  Das Hexacarbaboran arachno‐C6B6H12 und ein methyliertes Pentacarbaboran arachno‐CH3C5B7H12: Bereiche mit beginnenden Kohlenwasserstoffeigenschaften in Boranclustern , 1999 .

[54]  W. Mcfarlane,et al.  A 13C and 31P magnetic double resonance study of organo-phosphorus compounds , 1968, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[55]  J. Valliant,et al.  The medicinal chemistry of carboranes , 2002 .

[56]  J. Kennedy,et al.  NMR Studies on Halogeno-cis-bis(phosphine)-nido-pentaboranyl Derivatives of Nickel, Palladium, and Platinum , 1979 .

[57]  W. Hutton,et al.  Two-dimensional boron-11−boron-11 nuclear magnetic resonance spectroscopy as a probe of polyhedral structure: application to boron hydrides, carboranes, metallaboranes, and metallacarboranes , 1984 .

[58]  J. Kennedy,et al.  Metallaborane reaction chemistry. Part 10. Phenylacetylene incorporation via [4,4-(PMe2Ph)2-arachno-4-PtCB8H12] in a ‘converse’ metalladicarbaborane synthesis of [7,7-(PMe2Ph)2-isonido-7,6,8-PtC2B6H7-6-Ph] , 2005 .

[59]  J. Ayllón,et al.  IRIDIUM COORDINATION TO EXO-DITHIO-7,8-DICARBA-NIDO-UNDECABORATE DERIVATIVES , 1994 .