TY  - JOUR
A1  - Wei, Yuxiang
A1  - Wang, Junyi
A1  - Yang, Weiguang
A1  - Lin, Zhenyang
A1  - Ye, Qing
T1  - Boosting Ring Strain and Lewis Acidity of Borirane: Synthesis, Reactivity and Density Functional Theory Studies of an Uncoordinated Arylborirane Fused to o‐Carborane
JF  - Chemistry – A European Journal
N2  - Among the parent borirane, benzoborirene and ortho‐dicarbadodecaborane‐fused borirane, the latter possesses the highest ring strain and the highest Lewis acidity according to our density functional theory (DFT) studies. The synthesis of this class of compounds is thus considerably challenging. The existing examples require either a strong π‐donating group or an extra ligand for B‐coordination, which nevertheless suppresses or completely turns off the Lewis acidity. The title compound, which possesses both features, not only allows the 1,2‐insertion of P=O, C=O or C≡N to proceed under milder conditions, but also enables the heretofore unknown dearomative 1,4‐insertion of Ar−(C=O)− into a B−C bond. The fusion of strained molecular systems to an o‐carborane cage shows great promise for boosting both the ring strain and acidity.
KW  - borirane
KW  - carborane
KW  - fused boracycles
KW  - Lewis acidity
KW  - ring strain
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312089
VL  - 29
IS  - 5
ER  - 
TY  - JOUR
A1  - Jos, Swetha
A1  - Szwetkowski, Connor
A1  - Slebodnick, Carla
A1  - Ricker, Robert
A1  - Chan, Ka Lok
A1  - Chan, Wing Chun
A1  - Radius, Udo
A1  - Lin, Zhenyang
A1  - Marder, Todd B.
A1  - Santos, Webster L.
T1  - Transition Metal‐Free Regio‐ and Stereo‐Selective trans Hydroboration of 1,3‐Diynes: A Phosphine‐Catalyzed Access to (E)‐1‐Boryl‐1,3‐Enynes
JF  - Chemistry – A European Journal
N2  - We report a transition metal‐free, regio‐ and stereo‐selective, phosphine‐catalyzed method for the trans hydroboration of 1,3‐diynes with pinacolborane that affords (E)‐1‐boryl‐1,3‐enynes. The reaction proceeds with excellent selectivity for boron addition to the external carbon of the 1,3‐diyne framework as unambiguously established by NMR and X‐ray crystallographic studies. The reaction displays a broad substrate scope including unsymmetrical diynes to generate products in high yield (up to 95 %). Experimental and theoretical studies suggest that phosphine attack on the alkyne is a key process in the catalytic cycle.
KW  - enediyne
KW  - enyne
KW  - hydroboration
KW  - organocatalytic
KW  - stereoselective
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-293784
VL  - 28
IS  - 63
ER  - 
TY  - JOUR
A1  - Lindl, Felix
A1  - Guo, Xueying
A1  - Krummenacher, Ivo
A1  - Rauch, Florian
A1  - Rempel, Anna
A1  - Paprocki, Valerie
A1  - Dellermann, Theresa
A1  - Stennett, Tom E.
A1  - Lamprecht, Anna
A1  - Brückner, Tobias
A1  - Radacki, Krzysztof
A1  - Bélanger-Chabot, Guillaume
A1  - Marder, Todd B.
A1  - Lin, Zhenyang
A1  - Braunschweig, Holger
T1  - Rethinking Borole Cycloaddition Reactivity
JF  - Chemistry—A European Journal
N2  - Boroles are attracting broad interest for their myriad and diverse applications, including in synthesis, small molecule activation and functional materials. Their properties and reactivity are closely linked to the cyclic conjugated diene system, which has been shown to participate in cycloaddition reactions, such as the Diels-Alder reaction with alkynes. The reaction steps leading to boranorbornadienes, borepins and tricyclic boracyclohexenes from the thermal reaction of boroles with alkynes are seemingly well understood as judged from the literature. Herein, we question the long-established mechanistic picture of pericyclic rearrangements by demonstrating that seven-membered borepins (i. e., heptaphenylborepin and two derivatives substituted with a thienyl and chloride substituent on boron) exist in a dynamic equilibrium with the corresponding bicyclic boranorbornadienes, the direct Diels-Alder products, but are not isolable products from the reactions. Heating gradually converts the isomeric mixtures into fluorescent tricyclic boracyclohexenes, the most stable isomers in the series. Results from mechanistic DFT calculations reveal that the tricyclic compounds derive from the boranorbornadienes and not the borepins, which were previously believed to be intermediates in purely pericyclic processes.
KW  - pericyclic reaction
KW  - Boron
KW  - computational chemistry
KW  - isomer
KW  - isomerization
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256888
VL  - 27
IS  - 43
ER  -