TY  - JOUR
A1  - Hagspiel, Stephan
A1  - Fantuzzi, Felipe
A1  - Dewhurst, Rian D.
A1  - Gärtner, Annalena
A1  - Lindl, Felix
A1  - Lamprecht, Anna
A1  - Braunschweig, Holger
T1  - Adducts of the parent boraphosphaketene H\(_2\)BPCO and their decarbonylative insertion chemistry
JF  - Angewandte Chemie International Edition
N2  - The first examples of Lewis base adducts of the parent boraphosphaketene (H\(_2\)B-PCO) and their cyclodimers are prepared. One of these adducts is shown to undergo mild decarbonylation and phosphinidene insertion into a B−C bond of a borole, forming very rare examples of 1,2-phosphaborinines, B/P isosteres of benzene. The strong donor properties of these 1,2-phosphaborinines are confirmed by the synthesis of their π complexes with the Group 6 metals.
KW  - inorganic chemistry
KW  - phosphorus
KW  - boron
KW  - decarbonylation
KW  - heterocycles
KW  - ketenes
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256470
VL  - 60
IS  - 24
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  -