Hydrosilylation of Aldehydes and Formates Using a Dimeric Manganese Precatalyst

Tufan K. Mukhopadhyay, Chandrani Ghosh, Marco Flores, Thomas L. Groy, Ryan Trovitch

Research output: Contribution to journalArticle

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Abstract

The formally zero-valent Mn dimer [(Ph2PEtPDI)Mn]2 has been synthesized upon reducing (Ph2PEtPDI)MnCl2 with excess Na/Hg. Single crystal X-ray diffraction analysis has revealed that [(Ph2PEtPDI)Mn]2 possesses a η4-PDI chelate about each Mn center, as well as η2-imine coordination across the dimer. The chelate metrical parameters suggest single electron PDI reduction and EPR spectroscopic analysis afforded a signal consistent with two weakly interacting S = 1/2 Mn centers. At ambient temperature in the absence of solvent, [(Ph2PEtPDI)Mn]2 has been found to catalyze the hydrosilylation of aldehydes at loadings as low as 0.005 mol % (0.01 mol % relative to Mn) with a maximum turnover frequency of 9,900 min-1 (4,950 min-1 per Mn). Moreover, the [(Ph2PEtPDI)Mn]2-catalyzed dihydrosilylation of formates has been found to proceed with turnover frequencies of up to 330 min-1 (165 min-1 relative to Mn). These metrics are comparable to those described for the leading Mn catalyst for this transformation, the propylene-bridged variant (Ph2PPrPDI)Mn; however, [(Ph2PEtPDI)Mn]2 is more easily inhibited by donor functionalities. Carbonyl and carboxylate hydrosilylation is believed to proceed through a modified Ojima mechanism following dimer dissociation.

Original languageEnglish
Pages (from-to)3477-3483
Number of pages7
JournalOrganometallics
Volume36
Issue number18
DOIs
Publication statusPublished - Jan 1 2017

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Formates
Hydrosilylation
formates
Manganese
aldehydes
Aldehydes
Dimers
manganese
dimers
chelates
Imines
Spectroscopic analysis
spectroscopic analysis
propylene
X ray diffraction analysis
imines
carboxylates
ambient temperature
Paramagnetic resonance
Single crystals

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Cite this

Hydrosilylation of Aldehydes and Formates Using a Dimeric Manganese Precatalyst. / Mukhopadhyay, Tufan K.; Ghosh, Chandrani; Flores, Marco; Groy, Thomas L.; Trovitch, Ryan.

In: Organometallics, Vol. 36, No. 18, 01.01.2017, p. 3477-3483.

Research output: Contribution to journalArticle

Mukhopadhyay, Tufan K. ; Ghosh, Chandrani ; Flores, Marco ; Groy, Thomas L. ; Trovitch, Ryan. / Hydrosilylation of Aldehydes and Formates Using a Dimeric Manganese Precatalyst. In: Organometallics. 2017 ; Vol. 36, No. 18. pp. 3477-3483.
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