TY  - JOUR
A1  - Braunschweig, Holger
A1  - Krummenacher, Ivo
A1  - Mailänder, Lisa
A1  - Pentecost, Leanne
A1  - Vargas, Alfredo
T1  - Formation of a stable radical by oxidation of a tetraorganoborate
JF  - Chemical Communications
N2  - Herein, we describe the selective formation of a stable neutral spiroborate radical by one-electron oxidation of the corresponding tetraorganoborate salt Li[B(C\(_4\)Ph\(_4\))\(_2\)], formally containing a tetrahedral borate centre and a s-cis-butadiene radical cation as the spin-bearing site. Spectroscopic and computational methods have been used to determine the spin distribution and the chromism observed in the solid state.
KW  - tetraorganoborate salt
KW  - spiroborates
KW  - one-electron oxidation
KW  - spin distribution
KW  - chromism
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191321
VL  - 52
IS  - 43
ER  - 
TY  - JOUR
A1  - Witte, Robert
A1  - Arrowsmith, Merle
A1  - Lamprecht, Anna
A1  - Schorr, Fabian
A1  - Krummenacher, Ivo
A1  - Braunschweig, Holger
T1  - C−C and C−N Bond Activation, Lewis‐Base Coordination and One‐ and Two‐Electron Oxidation at a Linear Aminoborylene
JF  - Chemistry – A European Journal
N2  - A cyclic alkyl(amino)carbene (CAAC)‐stabilized dicoordinate aminoborylene is synthesized by the twofold reduction of a [(CAAC)BCl\(_{2}\)(TMP)] (TMP=2,6‐tetramethylpiperidyl) precursor. NMR‐spectroscopic, X‐ray crystallographic and computational analyses confirm the cumulenic nature of the central C=B=N moiety. Irradiation of [(CAAC)B(TMP)] (2) resulted in an intramolecular C−C bond activation, leading to a doubly‐fused C\(_{10}\)BN heterocycle, while the reaction with acetonitrile resulted in an aryl migration from the CAAC to the acetonitrile nitrogen atom, concomitant with tautomerization of the latter to a boron‐bound allylamino ligand. One‐electron oxidation of 2 with CuX (X=Cl, Br) afforded the corresponding amino(halo)boryl radicals, which were characterized by EPR spectroscopy and DFT calculations. Placing 2 under an atmosphere of CO afforded the tricoordinate (CAAC,CO)‐stabilized aminoborylene. Finally, the twofold oxidation of 2 with chalcogens led, in the case of N\(_{2}\)O and sulfur, to the splitting of the B−C\(_{CAAC}\) bond and formation of the 2,4‐diamino‐1,3,2,4‐dichalcogenadiboretanes and CAAC‐chalcogen adducts, whereas with selenium a monomeric boraselenone was isolated, which showed some degree of B−Se multiple bonding.
KW  - bond activation
KW  - boraselenone
KW  - dicoordinate borylene
KW  - one-electron oxidation
KW  - push-pull stabilization
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312491
VL  - 29
IS  - 16
ER  -