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. 2020 Nov 9;39(21):3771-3774.
doi: 10.1021/acs.organomet.0c00577. Epub 2020 Oct 20.

Generation of Masked TiII Intermediates from TiIV Amides via β-H Abstraction or Alkyne Deprotonation: An Example of Ti-Catalyzed Nitrene-Coupled Transfer Hydrogenation

Adam J Pearce  1 , Yukun Cheng  1 , Rachel J Dunscomb  1 , Ian A Tonks  1
Affiliations

Generation of Masked TiII Intermediates from TiIV Amides via β-H Abstraction or Alkyne Deprotonation: An Example of Ti-Catalyzed Nitrene-Coupled Transfer Hydrogenation

Adam J Pearce et al. Organometallics. .

Abstract

Simple Ti amide complexes are shown to act as sources for masked TiII intermediates via several pathways, as demonstrated through the investigation of a unique Ti-catalyzed nitrene-coupled transfer hydrogenation of 3-hexyne. This reaction proceeds through reduction of azobenzene by a masked TiII catalyst, wherein both amines and 3-hexyne can serve as the hydrogen source/reductant for Ti by forming putative titanaziridines via β-H abstraction or putative titanacyclopentynes via protonolysis, respectively.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1.
Figure 1.
Masked TiII reagents generated via β-H abstraction by Ti alkyls (top) or Ti amides (bottom).
Figure 2.
Figure 2.
Plausible mechanism of hydroamination of 3-hexyne with azobenzene catalyzed by TiCl2(NMe2)2. Teal and black hydrogens indicate their origin from −NMe2 or 3-hexyne, respectively.
See this image and copyright information in PMC

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