Synthesis and Structure of a 1,2,4,5‐Tetraborinane

Abstract

Stabilization of the B4C2 skeleton as a classical boron‐carbon compound with cyclohexane structure has been achieved for the first time by introduction of electronically active dimethylamino groups. In the crystal, 2 adopts a chair conformation. Because they are electron deficient, compounds of the type (RB)4(CR′)2, R,R′ = H, alkyl, have carbaborane structures.

Isolation of Free Phenylide-like Carbanions with N-Heterocyclic Carbene Frameworks

“…The ionic precursors 1 were prepared cleanly and in high yield via the ring-closing reaction of silylated bis(2,6-diisopropylphenyl)formamidine with 1,1-bis(organochloroboryl)ethane in the presence of Me 3 SiOTf, as described for imidazolium analogs incorporating inorganic backbones. , The phenyl derivative MeCH(PhBCl) 2 was synthesized through the metathesis reaction of 1,1-MeCH(BCl 2 ) 2 with SnPh 4 , while MeCH(Me 2 NBCl) 2 was obtained via the reaction of MeCH(BCl 2 ) 2 with Me 3 SiNMe 2 . The 1 H NMR spectrum of 1c displayed the resonances expected for a solvent-separated ion pair with C s symmetry of the cation, as observed for 1a .…”

“…The solvents were dried and deoxygenated prior to use. Derivatives 1a − 3a , as well as MeCH(RBCl) 2 (R = Ph, Me 2 N) , and (2,6- i Pr 2 C 6 H 3 )NCH−N(SiMe 3 )(2,6- i Pr 2 C 6 H 3 ), were prepared according to literature procedures. All NMR spectra were run on a Bruker Avance DRX-400 instrument and chemical shifts are reported in δ units (ppm) using the solvent as an internal reference: C 6 D 6 H (7.15 ppm, 1 H) and C 6 D 6 (128.0 ppm, 13 C); THF- d 7 (3.58 ppm, 1 H) and THF- d 8 (67.57 ppm, 13 C).…”