Enthalogenierung von Aminodihalogenboranen durch Na/K‐Legierung in Gegenwart von Naphthalin, Bis(trimethylsilyl)butadiin und 2,5‐Dimethyl‐2,4‐hexadien

Abstract

Reaction of naphthalene with Na/K alloy and [(2,6-diisopro-dimethyl-2,4-hexadiene with dichloro(diisopropy1amino)borpylphenyl)methylamino]difluoroborane (1) in 1,Zdimethoxy-ane to Na/K alloy in hexane the 2,4,5triborabicycloethane yields the aminodimethoxyborane 2, the bis(amino)-[l.l.l]pentane 7 and the diboretane 8, resp., are obtained. 'H-, borane 3, the diborylethyne 4, and the diboryl oxide 5. By "B-, 13C-, "F-, *'Si-NMR-, IR, and MS data are given. For 2-4, addition of a mixture of bis(trimethylsily1)butadiyne or 2,5-7 and 8 X-ray structure analyses are performed.

1,1,1-Trisborylalkanes as Precursors for Dicarbapentaboranes(5) − Synthesis, Reactivity, and Structures ofcloso-1,5-Bis(neopentyl)-2,3,4-trichloro-1,5-dicarbapentaborane and Its Derivatives

“…When 6a was treated with pentamethylsilazane at Ϫ30°C (Scheme 5), colorless 6c was formed as a solid in good yields. Its 11 B NMR spectrum showed a signal at δ ϭ 21.3, in agreement with the reported [7,8] amino-substituted closo-(RC) 2 (BNiPr 2 ) 3 . In the 1 H and 13 C NMR spectra, the expected signals for the tert-butyl, dimethylamino, and methylene groups were found, although no resonance was detected for the quaternary CB 3 carbon atom.…”

“…In the C 2 B 3 framework, the BϪB [1.842(3)Ϫ1.855 (3) Å ] and BϪC distances [1.541(3)Ϫ1.586(3) Å ] are in the range of the corresponding values for the parent closo-C 2 B 3 H 5 , determined by electron diffraction. [17] The BϪB bond lengths are substantially shorter than the structure data [1.965(8) Å ] published by Meller et al, [7,8] who classified their molecules as bicycles. The BϪB distances in 6a are somewhat shorter than those in the carborane C 2 B 3 Et 5 reported by Köster et al [6] [1.876(4) Å ].…”

“…[6] The closo-C 2 B 3 -carboranes warrant particular interest because their structure and bonding may be described as midway between classical and nonclassical. In the last decade, the structures of these smallest closo-carboranes have been elucidated by X-ray diffraction analyses of amino-substituted derivatives [7,8] and pentaethyl-1,5-dicarba-closo-Compound 6a reacted with methyllithium and trimethylaluminium, and also with pentamethylsilazane and acetylides, to give the corresponding carborane derivatives 6c, 6d, 6e, and 6f. The compositions of the products followed from analytical data and X-ray structure analyses of 1b, 4b, 5b, 6a, and 6f.…”

1,1,1-Trisborylalkanes as Precursors for Dicarbapentaboranes(5) − Synthesis, Reactivity, and Structures of closo-1,5-Bis(neopentyl)-2,3,4-trichloro-1,5-dicarbapentaborane and Its Derivatives

“…The highest peak observed in an EI mass spectrum of 6a was found at m/z ϭ 289 [M ϩ Ϫ CH 3 ], but the PICI mass spectrum showed [M ϩ ] at m/z ϭ 303 as the base peak. Its 11 B NMR spectrum showed a signal at δ ϭ 21.3, in agreement with the reported [7,8] amino-substituted closo-(RC) 2 (BNiPr 2 ) 3 . The trimethyl derivative 6d may be obtained by two routes (Scheme 4).…”

“…[4] In 1995 a new route to pentaethyl-1,5-dicarba-closo-pentaborane (5) was established, through the use of a large excess of (Et 2 BH) 2 as a ''hydride bath'' to give a 1-carba-arachnopentaborane(10) derivative [5] as precursor. In the last decade, the structures of these smallest closo-carboranes have been elucidated by X-ray diffraction analyses of amino-substituted derivatives [7,8] and pentaethyl-1,5-dicarba-closo-Compound 6a reacted with methyllithium and trimethylaluminium, and also with pentamethylsilazane and acetylides, to give the corresponding carborane derivatives 6c, 6d, 6e, and 6f. [6] The closo-C 2 B 3 -carboranes warrant particular interest because their structure and bonding may be described as midway between classical and nonclassical.…”