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Abstract Group I alkoxides are highly active precatalysts in the heterodehydrocoupling of silanes and amines to afford aminosilane products. The broadly soluble and commercially available KOtAmyl was utilized as the benchmark precatalyst for this transformation. Challenging substrates such as anilines were found to readily couple primary, secondary, and tertiary silanes in high conversions (>90 %) after only 2 h at 40 °C. Traditionally challenging silanes such as Ph3SiH were also easily coupled to simple primary and secondary amines under mild conditions, with reactivity that rivals many rare earth and transition‐metal catalysts for this transformation. Preliminary evidence suggests the formation of hypercoordinated intermediates, but radicals were detected under catalytic conditions, indicating a mechanism that is rare for Si−N bond formation.
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Two Paths to Oxidative C−H Amination Under Basic Conditions: A Theoretical Case Study Reveals Hidden Opportunities Provided by Electron Upconversion**
Abstract Traditionally, cross‐dehydrogenative coupling (CDC) leads to C−N bond formation under basic and oxidative conditions and is proposed to proceed via a two‐electron bond formation mediated by carbenium ions. However, the formation of such high‐energy intermediates is only possible in the presence of strong oxidants, which may lead to undesired side reactions and poor functional group tolerance. In this work we explore if oxidation under basic conditions allows the formation of three‐electron bonds (resulting in “upconverted” highly‐reducing radical‐anions). The benefit of this “upconversion” process is in the ability to use milder oxidants (e. g., O2) and to avoid high‐energy intermediates. Comparison of the two‐ and three‐electron pathways using quantum mechanical calculations reveals that not only does the absence of a strong oxidant shut down two‐electron pathways in favor of a three‐electron path but, paradoxically, weaker oxidants react faster with the upconverted reductants by avoiding the inverted Marcus region for electron transfer.
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- Award ID(s):
- 2102579
- PAR ID:
- 10370379
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 28
- Issue:
- 60
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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