Facile Access to Unprecedented Electron-Precise Monohydrodiboranes(4), cis-1,2-Dihydrodiboranes(4), and a 1,1-Dihydrodiborane(5)

Merle Arrowsmith; Holger Braunschweig; Krzysztof Radacki; Torsten Thiess; Arthur Turkin

doi:10.1002/chem.201605270

Facile Access to Unprecedented Electron-Precise Monohydrodiboranes(4), cis-1,2-Dihydrodiboranes(4), and a 1,1-Dihydrodiborane(5)

Chemistry. 2017 Feb 10;23(9):2179-2184. doi: 10.1002/chem.201605270. Epub 2017 Jan 12.

Authors

Merle Arrowsmith^{1

2}, Holger Braunschweig^{1

2}, Krzysztof Radacki^{1

2}, Torsten Thiess^{1

2}, Arthur Turkin^{1

2}

Affiliations

¹ Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
² Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.

PMID: 27935652
DOI: 10.1002/chem.201605270

Abstract

2,3-Bis(dimethylamino)-substituted B₂ N₂ C₂ heterocycles underwent selective dimethylamino/hydride exchange with either one or two equivalents of BH₃ ⋅SMe₂ to give the corresponding cyclic monohydrido- or (cis)1,2-dihydridodiboranes(4), respectively. Upon either heating or irradiation in solution, the latter underwent ring contraction to the corresponding five-membered BN₂ C₂ heterocycles, whereas irradiation of the 1,2-dimethylaminoethene-supported 1,2-dihydridodiborane(4) in the presence of PEt₃ gave an unprecedented unsymmetrical 1,1-dihydrodiborane(5) phosphine adduct.

Keywords: diboranes; heterocycles; hydride ligands; isomerization; ring contraction.