Darstellung und Reaktionen von 1,1,2,2‐Tetraborylethan‐Derivaten

Abstract

Synthesis and Reactions of lJ.2.2-Tetraborylethane Derivatives *Reaction of (Z)-1,2-bis(dichloroboryl)ethene with B2C14 leads to l,l,Z,Z-tetrakis(dichloroboryl)ethane ( l a ) in 90% yield. Substitution of the chlorine atoms in l a results in the formation of the iodo and amino derivatives 1 b and 1 c, d. Compound 1 b reacts with alkynes to give the 2,2'-linked 2,3-dihydro-1,3-diborole derivatives 2b, c which are aminated to yield 2d, e. Dehalogenation of 1 d leads to the organoboron C2B4 cage 3d.The heterobicyclic compound 4d with two fused phosphadiborolane rings is obtained from Id and LiPH2. Reaction of 4d with (C0)3Fe(C8H14)2 gives the unusual diiron complex 5d. The constitutions of the new compounds are derived from spectroscopic data and are proven for 2e, 4d and 5d by X-ray structure analyses.

Synthesis of Tetraborylethenes and 1,1,1′,1′-Tetra- and Hexaborylethanes; Electronic Interactions in Tetraborylethenes and 1,1,1′,1′-Tetraborylethanes, and HF-SCF Calculations

“…1.575 Å ), and comparable with that of other characterized tetraborylethane derivatives. [6] Calculated Geometrical Parameters for 5a…”

“…[5] Further reaction of (CH) 2 (BCl 2 ) 2 with B 2 Cl 4 affords tetrakis(dichloroboryl)ethane in excellent yield. [6] Recently a tetraborylethane was proposed as an intermediate in the hydroboration of bis(diethylboryl)acetylene, which rearranges to give carborane clusters. [7] Diboration of ethenes to 1,2-diborylethanes can be achieved by using bis(1,5-Results and Discussion cyclooctadiene)platinum [8] [Pt(cod) 2 ], tris(norbornene)…”

“…The precipitate was then heated in 35 mL of THF at 55°C for 24 h. The solvent was evapommol) of 5a was suspended with 70 mg of a palladium/active C6 H 4 O 2 BOCD 3 ). Ϫ CI-MS: m/z (%) 500 (100) [M ϩ ], 501 (78.4) [M carbon catalyst in 100 mL of toluene.…”

Intramolekular verbrückte Organo-bis[dialkylaminochlorborane] / Intramolecularly Bridged Organo-bis[dialkylaminochloroboranes]

“…3 liegt bei 25°C zu > 90% in der einfach verbrückten Form vor; eine doppelte Verbrückung unter B eteili gung der übrigen B or-atom e wird nicht beobachtet [6], In c/s-2,3-B is(dim ethylam inochlorboryl)-but-2-en (4, R = M e) erlauben die D im ethylam inoSubstituenten ebenfalls eine einfache intram oleku lare A dduktbildung [5]. l-Chlordimethylaminoboryl-2-chlorodimethylaminoborylmethyl-benzol (9) [13] …”

B2F4 Molecule: A Challenge for Theoretical Calculations

“…B 2 X 4 (X ) F, Cl, Br) molecules are important precursors for synthesizing boron-containing compounds. [1][2][3][4][5] Similar to other isoelectonic molecules with 34 valence electrons, such as N 2 O 4 and C 2 Y 4 2+ (Y ) H, F, Cl, Br, OR), the structures of the three B 2 X 4 molecules strongly depend on substituent X. B 2 Br 4 was known to be staggered (D 2d symmetry) in all thee phases (solid, liquid, and gas).…”