Enabling and Probing Oxidative Addition and Reductive Elimination at a Group 14 Metal Center: Cleavage and Functionalization of E–H Bonds by a Bis(boryl)stannylene

• Published in: Journal of the American Chemical Society Vol. 138; no. 13; pp. 4555 - 4564
• Main Authors: Protchenko, Andrey V, Bates, Joshua I, Saleh, Liban M. A, Blake, Matthew P, Schwarz, Andrew D, Kolychev, Eugene L, Thompson, Amber L, Jones, Cameron, Mountford, Philip, Aldridge, Simon
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 06.04.2016; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology; HYDROGEN; ACTIVATION; DIHYDROGEN; ETHYLENE; AMMONIA; APPROXIMATION; N-HETEROCYCLIC SILYLENE; 2-COORDINATE; REACTIVITY; CRYSTAL-STRUCTURES
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.6b00710

By employing strongly σ-donating boryl ancillary ligands, the oxidative addition of H2 to a single site SnII system has been achieved for the first time, generating (boryl)2SnH2. Similar chemistry can also be achieved for protic and hydridic E–H bonds (N–H/O–H, Si–H/B–H, respectively). In the case of ammonia (and water, albeit more slowly), E–H oxidative addition can be shown to be followed by reductive elimination to give an N- (or O-)­borylated product. Thus, in stoichiometric fashion, redox-based bond cleavage/formation is demonstrated for a single main group metal center at room temperature. From a mechanistic viewpoint, a two-step coordination/proton transfer process for N–H activation is shown to be viable through the isolation of species of the types Sn­(boryl)2·NH3 and [Sn­(boryl)2(NH2)]− and their onward conversion to the formal oxidative addition product Sn­(boryl)2(H)­(NH2).