4375-83-1Relevant articles and documents
BEITRAEGE ZUR CHEMIE DES BORS. CLXXII. DARSTELLUNG, STRUKTUR UND REAKTIONEN VON μ-(BORANDITHIOLATO)BIS(TRICARBONYLEISEN)-VERBINDUNGEN, XBS22
Noeth, Heinrich,Rattay, Wilfried
, p. 131 - 152 (1986)
Li2S2Fe2(CO)6 and M2S2Fe2(CO)6nBEt3 (M=Li, Na) have been used to prepare a wide range of the compounds XBS2Fe2(CO)6 (X=NR2, R, Hal) as well as the μ-(bis(dimethylamino)diborane(4)di-thiolato) derivative (4).Reaction of Li2S2Fe2(CO)6 with 2-chloro-1,3-dimethyl-1,3,2-diazaborolidine yields a spirocyclic product.The Me2N group in the Me2NBS2Fe2(CO)6 can be readily exchanged for chlorine or bromine using the respective boron halides as electrophilic reagents.Similarly, 4 can be transformed into the dimethylamino-chloro or -bromo derivatives.Further substitution, using BCl3 and Me2N(Cl)B2S2Fe2(CO)6 leads to Cl2B2S2Fe2(CO)6, which can be de tected by 11B NMR at low temperature, but the compound decomposes at ambient temperature to produce ClBS2Fe2(CO)6.Nucleophilic displacement of Cl- for OtBu- or R- is readily achieved by treating ClBS2Fe2(CO)6 with KOtBu or LiBu.Attack at the B-S bond has not been observed.The electron density at the iron atoms is only influenced marginally by the various boron substituents as shown by ν(CO); therefore electronic effects are not transduced via the sulfur atoms to the metal atoms.The X-ray structures, which have been determined for tmpBS2Fe2(CO)6 (3), (Me2NB)2S2Fe2(CO)6 (4) and 2S2Fe2(CO)6 (6b) show only slight variations in the S2Fe2 units; a larger S...S separation results in 4 due to the bridging diborane(4) unit.
Alkoxide activation of aminoboranes towards selective amination
Sole, Cristina,Fernandez, Elena
supporting information, p. 11351 - 11355 (2013/11/06)
Piece of the (inter)action: The interaction of alkoxides with the sp 2 Bpin (pin=pinacol) moiety in aminoboranes forms the in situ Lewis acid-base adduct [RO-→B(OR)2-N(R′)2] which enables the amino moiety to react as a strong nucleophile with several electrophiles, thus providing amino alcohols, β-enamino esters, and β-hydroxy amides in a direct and remarkably selective way (see scheme). Copyright
Metal Hydroborates and Hydroborato Metalates, 21. Solvates of Lithium (Dimethylamino)trihydroborate
Noeth, Heinrich,Thomas, Steffen,Schmidt, Martin
, p. 451 - 458 (2007/10/03)
Li(Me2NBH3) (1) was prepared by deprotonation of Me2NH*BH3 with LiBu and its solubility determined in various solvents.Compound 1 is unstable in most etheral solvents and decomposes in a reversible reaction into LiH and Li(Me2N-BH2-NMe2-BH3) (2).Five solvates of 1 were characterised by X-ray structure analysis.Li(Me2NBH3)*TMEDA is a dimer in the solid state, and two units are connected to one another by B-H...Li bonds.The crystal structure of Li(Me2NBH3)*0.5 dioxane is represented by layers consisting of tetrameric Li(Me2NBH3) units connected via dioxane molecules.Each Li atom is coordinated to one oxygen atom, one nitrogen atom, and two hydrogen atoms.Also Li(Me2NBH3)*0.5 O2C3H6 forms an extended layer, however with pentacoordinated Li atoms which bear one oxygen, one nitrogen, and three hydrogen atoms.A similar layer structure was also found for Li(Me2NBH3)*O3C3H6 where each Li atom is bound to two oxygen atoms of different trioxane molecules, one nitrogen atom, and two hydrogen atoms.Finally, Li(Me2NBH3)*12-crown-4 retains its molecular integrity in the solid state.Its Li atom is pentacoordinated by four oxygen atoms and one nitrogen atom. - Keywords: Borate lithium (dimethylamino)trihydrido- / TMEDA complex / Dioxane complex / 12-Crown-4 complex
Borabenzene derivatives. 22. Synthesis of boratabenzene salts from 2,4-pentadienylboranes. Structure of [NMe3Ph][C5H5BMe]
Herberich, Gerhard E.,Schmidt, Bernd,Englert, Ulli
, p. 471 - 480 (2008/10/08)
Borylation of potassium pentadienide with BCl(NR2)2 and subsequent alcoholysis produce 2,4-pentadienylboranes C5H7B(NR2)2 (4a-c: R = Me, Et, Pri), C5H7B(OR)2 (4e,f: R = Et, But), and C5H7B(OCR2)2 with 1,3,2-dioxaborolane rings (4g,h: R = H, Me) as mixtures of E and Z isomers. Metalation of 4a,b in THF by lithium dialkylamides LiNR′2 (R′ = Me, Et, Pri) in the presence of TMEDA results (i) in a nonproductive deborylation via primary attack at the boron center, (ii) in ring closure to produce boratabenzene salts [Li(TMEDA)][C5H5-BNR2] (10a,b: R = Me, Et), and (iii) in substitution of B-dialkylamino groups when NR2 is bulkier than NR′2. 10a is obtained in 26.5% yield. Metalation of 4h in THF by the sterically demanding lithium dialkylamides LDA and LiTMP affords a precipitate of the spiroborate [Li(THF)][C5H6B(OCMe2)2] (13) in 63% yield in equilibrium with the presumed isomer Li-[C5H5BO(CMe2)2OH] (Li(3g)) in the THF solution. 13 can be transformed into boratabenzenes by several methods. (i) Treatment with Me3SiCl produces a 1:1 mixture of isomeric boracyclohexadienes C5H6BOCMe2CMe2OSiMe3 (15a, 2,4-isomer; 15b, 2,5-isomer) which, on subsequent low-temperature metalation, give Li[C5H5BO(CMe2)OSiMe3] (Li(3h)). (ii) Metalation of 13 at -78°C affords Li2[C5H5BO(CMe2)O] (Li2(3i)) and, after treatment with Me3SiCl, the bora-2,4-cyclohexadiene (5-Me3Si)C5H5BOCMe2CMe 2OSiMe3 (16). (iii) Treatment of 13 with Al2Me6 in toluene at -78°C affords Li[C5H5BMe] (Li(3b)) in 79% yield as a white solid. This salt is also obtained from Li(3h) and Al2Me6. (iv) Addition of 15 to LiBut in pentane/hexane produces Li[C5H5BBut] (Li(3c)) in 53% yield. Combining strongly alkaline aqueous solutions of [NMe3Ph]I and Li(3b) affords [NMe3Ph][C5H5BMe] (18). 18 crystallizes in the monoclinic space group P21/n with a = 935.4(1) pm, b = 1557.4(4) pm, c = 988.8(1) pm, β = 95.47(1)°, and Z = 4. The 1-methylboratabenzene ion of 18 displays nearly perfect C2v symmetry with intra-ring bond distances of 150.1, 138.8, and 139.2 pm (average) for B-C1 (B-C5), C1-C2 (C4-C5), and C2-C3 (C3-C4), respectively.
Dialkylamino- and alkoxytrialkylstannanes as reagent for synthesis of organoboryl (trialkylsilyl) ketenes
Nikolaeva, S. N.,Zolotareva, A. S.,Ponomarev, S. V.,Petrosyan, V. S.
, p. 857 - 861 (2007/10/02)
Dialkylamino- and alkoxytrialkylstannanes have been studied as N- and O-nucleophilic reagents in substitution reactions at the B-Br bond.The previously unknown bis(dialkylamino)- and dialkoxyboryl trialkylsilyl ketenes were synthesized.Some peculiarities of the reactivity of these compounds have been studied. - Key words: dialkylaminotrialkylstannane, alkoxytrialkylstannane, synthesis; borylsilyl ketene, methanolysis, aminolysis.
Single-source molecular organic chemical vapor deposition agents and use
-
, (2008/06/13)
Neutral single-source molecular organic precursors containing tetradentate tripodal chelating ligands are provided that are useful for the preparation of films using chemical vapor deposition. These complexes can be generally represented by the formula STR1 wherein M is selected from the group consisting of a lanthanide, an actinide, a Group IIIA metal, a Group IIIA metalloid, a Group IVA metal, a Group IVA metalloid, a Group VA metal, a Group VA metalloid, a Group IIIB metal, a Group IVB metal, a Group VB metal, a Group VIB metal, a Group VIIB metal, and a Group VIIIB metal. The ligand Z can be present or absent, i.e., k=0-1, and is selected from the group consisting of hydrogen, halide, and a group bonded to M through N, O, P, S, As, Si, or C. In the tetradentate tripodal chelating ligand Ec is N, P, or As, and m=0-1. When Et is N, P, or As, m=1, and when Et is O, S, or Se, m=0. Each R1 is independently selected from the group consisting of hydrogen, (C1 -C20)alkyl, (C2 -C20)alkenyl, (C2 -C20)alkynyl, (C6 -C18)aryl, (C7 -C20)aralkyl, a (C5 -C18)heterocycle, and triorganosilyl. In --[C(R2)2 ]n --, n=1-4, and each R2 is independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, aryl, aralkyl, and a heterocycle.
Contribution to the Chemistry of Boron, 224 Reactions and Structure of Electron-Precise Triborane(5) and Tetraborane(6) Derivatives
Linti, Gerald,Loderer, Dirk,Noeth, Heinrich,Polborn, Kurt,Rattay, Wilfried
, p. 1909 - 1922 (2007/10/02)
An improved synthesis of B3(NMe2)5 (2), B4(NMe2)6 (1), and B6(NMe2)8 (4) is reported.From each compound two of the four terminal dimethylamino groups are readily replaced by halogen atoms yielding α,ω-dihalides Bn(NMe2)nX2 (n = 3, 4; X = Cl, Br, I).These are used in turn to replace the substituent X by groups like RO, RS, RHN, R2P, and R.Crystal structure determinations on several of these compounds reveal as a common feature planar (C2N)BB2 and (C2N)B(B)X groups which are arranged in an approximately orthogonal manner to one another with NBBN dihedral angles ranging from 69 to 104.6 deg.Consequently, there is no significant ? bonding between the boron atoms. - Key Words: Triboranes(5), 1,ω-disubstituted / Tetraboranes(6), 1,ω-disubstituted / Hexaborane(8), octakis(dimethylamino)- / Electron-precise polyboranes
Borylation of Sulfamides, Sulfonimines and Sulfonediimines
Einholz, Wolfgang,Frey, Gerhard,Haubold, Wolfgang
, p. 47 - 54 (2007/10/02)
The diborylated sulfamide 6a can be obtained from 2-chloro-1,3-dimethyl-1,3,2-diazaborolidine and the silylated sulfamide 1a, whereas (Me2N)2BCl and 1a yield the dithiatetrazadiborocine 7b.Similarly, (Me2N)2BCl reacts with a) the sulfonimine 2a, b) the sulfonediimine 3a to give a) B(NMe2)3 and the bis- and tris(sulfonimino)boranes 10b and 11, b) B(NMe2)3 and the dithiatetrazadiborocine 15b.The diborylated sulfamide 6c (R2B = Ph2B) cannot be isolated.The synthesis of the monoborylated sulfonimines 9c, 9e and sulfonediimines 13, 14 is described. - Keywords: Boron-Nitrogen Compounds, Borylated Sulfamides, Sulfonimines, Sulfonediimines, Synthesis, Spectroscopic Data
BEITRAEGE ZUR CHEMIE DES BORS CLXXVII. DITHIADIBORETANE UND TRITHIATRIBORANE (BORTHIINE): KINETISCHE UND THERMODYNAMISCHE PRODUKT-KONTROLLE
Noeth, Heinrich,Rattay, Wilfried
, p. 139 - 148 (2007/10/02)
Thermal decomposition of μ-(aminoborondithiolato)bis(tricarbonyliron) compounds gives the 2,4-diamino-1,3,2,4-dithiadiboretanes (R2NBS)2 (R2N = NMe, NiPr2, tmp) at ca. 200 deg C. (Me2NBS)2 thus obtained reacts with itself in solution to give (Me2NBS)3.Therefore, the B2S2 compounds are the kinetically controlled products while the B3S3 ring systems represent the thermodynamic products.This is further substantiated by the thermolysis of PhBS2Fe2(CO)6 at 200 deg C which yields a mixture of (PhBS)2 with (PhBS)3, while pure (PhBS)2 is readily obtained from PhBCl2 and (Me3Si)2S under mild conditions.Pyrolysis of the diboron compound (Me2N)2B2S2Fe2(CO)6 proceeds with disproportionation leading to (Me2NBS)2 as the volatile products, while the spirocyclic iron cluster μ-(2,5,7,10-tetramethyl-2,10-diaza-5,7-diazonia-1,6-diboratotricyclo1,5>decane-6,6-dithiolato)bis(tricarbonyliron) yields bis(1,3-dimethyl-1,3,2-diazaborolidin-2-yl)sulfide.Silthiane cleavage of (Me2Si)2S with aminoboron halides R2NBX2 and (Me2N)2BCl require reflux conditions in toluene to give (R2NBS)2,3 heterocycles.
