TY  - JOUR
A1  - Roy, Dipak Kumar
A1  - Tröster, Tobias
A1  - Fantuzzi, Felipe
A1  - Dewhurst, Rian D.
A1  - Lenczyk, Carsten
A1  - Radacki, Krzysztof
A1  - Pranckevicius, Conor
A1  - Engels, Bernd
A1  - Braunschweig, Holger
T1  - Isolation and Reactivity of an Antiaromatic s‐Block Metal Compound
JF  - Angewandte Chemie International Edition
N2  - The concepts of aromaticity and antiaromaticity have a long history, and countless demonstrations of these phenomena have been made with molecules based on elements from the p, d, and f blocks of the periodic table. In contrast, the limited oxidation‐state flexibility of the s‐block metals has long stood in the way of their participation in sophisticated π‐bonding arrangements, and truly antiaromatic systems containing s‐block metals are altogether absent or remain poorly defined. Using spectroscopic, structural, and computational techniques, we present herein the synthesis and authentication of a heterocyclic compound containing the alkaline earth metal beryllium that exhibits significant antiaromaticity, and detail its chemical reduction and Lewis‐base‐coordination chemistry.
KW  - antiaromaticity
KW  - aromaticity
KW  - beryllium
KW  - heterocycles
KW  - s-block metals
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224447
VL  - 60
IS  - 7
SP  - 3812
EP  - 3819
ER  - 
TY  - JOUR
A1  - Lenczyk, Carsten
A1  - Roy, Dipak Kumar
A1  - Nitsch, Jörn
A1  - Radacki, Krzysztof
A1  - Rauch, Florian
A1  - Dewhurst, Rian D.
A1  - Bickelhaupt, F. Matthias
A1  - Marder, Todd B.
A1  - Braunschweig, Holger
T1  - Steric Effects Dictate the Formation of Terminal Arylborylene Complexes of Ruthenium from Dihydroboranes
JF  - Chemistry - A European Journal
N2  - The steric and electronic properties of aryl substituents in monoaryl borohydrides (Li[ArBH\(_3\)]) and dihydroboranes were systematically varied and their reactions with [Ru(PCy\(_3\))\(_2\)HCl(H\(_2\))] (Cy: cyclohexyl) were studied, resulting in bis(σ)‐borane or terminal borylene complexes of ruthenium. These variations allowed for the investigation of the factors involved in the activation of dihydroboranes in the synthesis of terminal borylene complexes. The complexes were studied by multinuclear NMR spectroscopy, mass spectrometry, X‐ray diffraction analysis, and density functional theory (DFT) calculations. The experimental and computational results suggest that the ortho‐substitution of the aryl groups is necessary for the formation of terminal borylene complexes.
KW  - Arylborylene Complexes
KW  - Ruthenium
KW  - Dihydroboranes
KW  - boranes
KW  - borohydrides
KW  - borylenes
KW  - steric effects
KW  - sigma boranes
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219537
SN  - 1521-3765
VL  - 25
IS  - 59
ER  - 
TY  - JOUR
A1  - Lenczyk, Carsten
A1  - Roy, Dipak Kumar
A1  - Oberdorf, Kai
A1  - Nitsch, Jörn
A1  - Dewhurst, Rian D.
A1  - Radacki, Krzysztof
A1  - Halet, Jean-François
A1  - Marder, Todd B.
A1  - Bickelhaupt, Matthias
A1  - Braunschweig, Holger
T1  - Toward Transition‐Metal‐Templated Construction of Arylated B\(_{4}\) Chains by Dihydroborane Dehydrocoupling
JF  - Chemistry - A European Journal
N2  - The reactivity of a diruthenium tetrahydride complex towards three selected dihydroboranes was investigated. The use of [DurBH\(_{2}\)] (Dur=2,3,5,6‐Me\(_{4}\)C\(_{6}\)H) and [(Me\(_{3}\)Si)\(_{2}\)NBH\(_{2}\)] led to the formation of bridging borylene complexes of the form [(Cp\(^{*}\)RuH)\(_{2}\)BR] (Cp\(^{*}\)=C\(_{5}\)Me\(_{5}\); 1 a: R=Dur; 1 b: R=N(SiMe\(_{3}\))\(_{2}\)) through oxidative addition of the B−H bonds with concomitant hydrogen liberation. Employing the more electron‐deficient dihydroborane [3,5‐(CF\(_{3}\))\(_{2}\)‐C\(_{6}\)H\(_{3}\)BH\(_{2}\)] led to the formation of an anionic complex bearing a tetraarylated chain of four boron atoms, namely Li(THF)\(_{4}\)[(Cp\(^{*}\)Ru)\(_{2}\)B\(_{4}\)H\(_{5}\)(3,5‐(CF\(_{3}\))\(_{2}\)C\(_{6}\)H\(_{3}\))\(_{4}\)] (4), through an unusual, incomplete threefold dehydrocoupling process. A comparative theoretical investigation of the bonding in a simplified model of 4 and the analogous complex nido‐[1,2(Cp\(^{*}\)Ru)\(_{2}\)(μ‐H)B\(_{4}\)H\(_{9}\)] (I) indicates that there appear to be no classical σ‐bonds between the boron atoms in complex I, whereas in the case of 4 the B\(_{4}\) chain better resembles a network of three B−B σ bonds, the central bond being significantly weaker than the other two.
KW  - transition metal
KW  - B−H activation
KW  - boron
KW  - dehydrocoupling
KW  - ruthenium
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214324
VL  - 25
IS  - 72
ER  -