Direct hydrosilylation by a zirconacycle with β-hydrogen

Area of Science:

• Organometallic Chemistry
• Silicon Chemistry
• Zirconium Chemistry

Background:

• Azasilazirconacycle Cp2Zr{κ(2)-N(SiHMe2)SiHMeCH2} (1) features 2-center-2-electron SiH groups.
• Reactions of related non-classical zirconacycles with carbonyls are known.
• Understanding the reactivity of novel organometallic compounds is crucial.

Purpose of the Study:

• To investigate the uncatalyzed reaction of azasilazirconacycle (1) with formaldehyde.
• To explore the reactivity of (1) with various nucleophilic and electrophilic agents.
• To elucidate the mechanism behind the observed hydrosilylation reaction.

Main Methods:

• Reaction of Cp2Zr{κ(2)-N(SiHMe2)SiHMeCH2} (1) with formaldehyde.
• Exploration of reactions with carbon monoxide, B(C6F5)3, OPEt3, and DMAP.
• Comparative analysis with non-classical zirconacycle compounds.

Main Results:

• An uncatalyzed hydrosilylation of formaldehyde by (1) yielded an exocyclic methoxysilyl-substituted zirconacycle.
• Reactions with CO and B(C6F5)3 occurred at the Zr-C bond, forming distinct products.
• (1) did not react with OPEt3 and DMAP, unlike related non-classical compounds.

Conclusions:

• The study reveals an unexpected hydrosilylation pathway for azasilazirconacycle (1) with formaldehyde.
• The reactivity of (1) differs from non-classical zirconacycles, particularly with OPEt3 and DMAP.
• The findings contribute to understanding the chemical behavior of β-SiH-containing silazidozirconium compounds.