7397-43-5Relevant academic research and scientific papers
Synthesis, molecular structure and reactivity of the dimethyl sulfide adduct of a 1,3,2-diselenaborolane with an annelated dicarba-closo- dodecaborane(12) unit
Wrackmeyer, Bernd,Klimkina, Elena V.,Milius, Wolfgang
, p. 2324 - 2334 (2010/09/06)
The reaction of 1,2-diselenolato-1,2-dicarba-closo-dodecaborane(12) dianion [1,2-(1,2-C2B10H10)Se2] 2- with HBBr2-SMe2 affords the dimethylsulfide adduct of 4,5-[1,2-dicarba-closo-dodecaborano(12)]-1,3-diselena -2-borolane in good yield. The molecular structure was determined by X-ray diffraction, and the solution-state structure was established by NMR spectroscopy (1H, 11B, 13C, 77Se NMR). 11B and 77Se chemical shifts were reproduced by DFT calculations. Attempts were made to abstract dimethyl sulfide, and the parent donor-free compound could be detected in solution. The reactivity of the title compound was studied towards pyridine, Me3SnF,[Pt(PPh3)2(C2H 4)], tert-Bu -OH, AlMe3 and AlH3-N(Et)Me 2 as well as a hydroborating reagent.
Metal tetrahydroborates and tetrahydroborato metallates, 30 [1]. Alkoxo-substituted alkali metal tetrahydroborates: Studies in solution and structures in the solid state
Knizek, J?rg,N?th, Heinrich,Warchhold, Markus
, p. 1079 - 1093 (2008/09/19)
Reactions of MBH4 (M = Li, Na, K) with tBuOH, Ph3COH, PhOH, F5C6OH, and 2,4-tBu2C6H 3OH in THF in a 1:1 ratio were followed by 11B NMR spectroscopy. No M[H2B(OR)2] species could be detected, but minor amounts of M[H3BOR] and larger amounts of M[HB(OR) 3]. In the reaction of LiBH4 with 2,4-tBu 2C6H3OH also a fair proportion of (RO) 2BH was generated. The perfluorophenolato borane (F5C 6O)2BH·THF was prepared from the phenol and BH 3·THF in THF solution. It is unstable to disproportionation. Compound (C6F5O)3B·THF was isolated and its crystal structure determined. Reaction of LiBH4 with F 5C6OH in hexane generated a solid that proved to be Li[H2B(OC6F5)2]. It is unstable in THF. On the other hand, 2,2′-dihydroxydiphenyl in the presence of secondary amines reacts to give Li[C12H8O 2B(NR2)2] (3-5). Li[B(O2C 12H8)2], 2, is formed when HN(tBu)Ph is used as a secondary amine. The unstable phthalatoborane H{C6H 4[C(O)O]2}BH·THF (7), is stabilized as its pyridine adduct (phth)BH·py (8). 7 reacts with 3 equivalents of LitBu to give [Li(HBtBu)3] (11), isolated as its tris(THF) solvate. Analogously, 7 reacts with LiNMePh to produce compound Li[HB(NMePh)3] (10). Similarly, 7 and NaOtBu (molar ratio 1:3) give access to Na[HB(OtBu) 3] (9). In attempts to grow single crystals, specimens resulting from a hexane solution showed that partial hydrolysis has occurred to give Na[HB(OtBu)3]·Na[(tBuO)2BO]·Na[tBuOB(O)H], which crystallizes as a centrosymmetric dimer. While catecholborane when treated with LitBu in THF and DME gave access to (dme)2Li[catB(tBu) 2], 12 (dme)2, several compounds were observed when Li piperidide was used as nucleophile. Amongst these, the most interesting one was (dme)(THF)Li2(cat)(catBH), 13 (dme)THF, the crystal structure of which was determined. In all cases where the borate species carried OR groups the O atoms of the RO or PhO group coordinate with the alkali metal cation. DFT calculations for the series of anions H4-nBXn- showed that HBX3- is the most stable species for X = F, OH, NH2. This confirms experimental results.
Convergent synthesis of alpha -aryl- beta -ketonitriles
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, (2008/06/13)
The present invention relates to processes for the production of alpha -aryl- beta -ketonitriles, which serve as synthetic intermediates in the preparation of a series of biologically important molecules such as corticotropin releasing factor (CRF) receptor antagonists.
Addition compounds of alkali-metal hydrides. 24. A general method for preparation of potassium trialkoxyborohydrides. A new class of reducing agents
Brown, Herbert C.,Cha, Jin Soon,Nazer, Behrooz
, p. 2929 - 2931 (2008/10/08)
The generality of the synthesis of potassium triisopropoxyborohydride, stabilized toward disproportionation by storing over excess potassium hydride, was examined with seven additional organoborates of varying steric requirements. The reaction of trimethoxy- and triethoxyborane with potassium hydride proceeded readily at room temperature, but the products could not be stabilized by the presence of excess potassium hydride. Triphenoxyborane reacted readily, even at -10°C, and stabilization was achieved. Tri-sec-butoxy- and tricyclopentoxyborane required refluxing in THF for 12-24 h, and the products were stabilized over potassium hydride. Finally, the reactions of tris(2-methylcyclohexoxy)- and tri-tert-butoxyborane were even slower, requiring a number of days for completion. Both products were stabilized toward disproportionation over potassium hydride. Indeed, potassium tri-tert-butoxyborohydride was quite stable toward disproportionation without excess potassium hydride. The stereoselectivities of these reagents in the reduction of representative cyclic ketones were examined. The stereoselectivities varied in an erratic manner with the steric requirements of the alkoxy group and did not approach the stereoselectivities previously achieved with lithium tri-sec-butylborohydride and lithium trisiamylborohydride.
Metall-Bor-Verbindungen, 13. Zur Synthese und Reaktivitaet einiger (Trimethylstannyl)borane
Noeth, Heinrich,Schwerthoeffer, Ruediger
, p. 3056 - 3062 (2007/10/02)
The preparation of some amino(trimethylstannyl)boranes and their chemical properties are described.With Me3SnLi (Me = CH3) as a reagent only the synthesis of Me3SnB(NR2)2 (1a, b), Me3SnBCl(NR2) (2a, b), and (Me3Sn)2BNR2 (3b) was achieved.The stannylboranes Me3SnB(NR2)2 show astonishing thermal stability.Their Sn - B bonds are broken by hydrogen, the halogens, and chalcogens as well as by alcohols.HCl cleaves the B - N bond.
