Dehydrogenative Silylation of Primary Alcohols Catalyzed
by [Au]-SMAP-Rh

doi:10.1055/s-2008-1078196

Synfacts 2008(10): 1111-1111
DOI: 10.1055/s-2008-1078196

Polymer-Supported Synthesis

Dehydrogenative Silylation of Primary Alcohols Catalyzed by [Au]-SMAP-Rh

Rezensent(en):Yasuhiro Uozumi, Yutaka Matsuura

K. Hara*, R. Akiyama, S. Takakusagi, K. Uosaki, T. Yoshino, H. Kagi, M. Sawamura*
Hokkaido University, Sapporo and The University of Tokyo, Japan
Self-Assembled Monolayers of Compact Phosphanes with Alkanethiolate Pendant Groups: Remarkable Reusability and Substrate Selectivity in Rh Catalysis
Angew. Chem. Int. Ed. 2008, 47: 5627-5630

Abstract

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Key words

heterogeneous catalysis - monolayers - phosphine ligands - rhodium

Significance

<P>Immersion of the gold surface in a solution of phosphine 1 in EtOH afforded [Au]-SMAP 2. [Au]-SMAP 2 was treated with a solution of [RhCl(C₂H₄)₂]₂ in benzene to give [Au]-SMAP-Rh 3. ICP-MS measurement of 3 revealed that rhodium was incorporated at a concentration of 0.63 nmol/cm^². [Au]-SMAP-Rh 3 was found to promote the dehydrogenative silylation of primary alcohols 4 to afford the corresponding silyl ether 5a-d with high TON up to 68,000 (eq. 1).</P>

Comment

<P>The silylation reaction of a mixture of primary alcohol 4a and secondary alcohol 4e with [Au]-SMAP-Rh gave silyl ether 5a, exclusively, without the formation of 5e (eq. 2). Catalyst 3 was reused three times in the dehydrogenative silylation of EtOH through which a total TON of 235,000 was achieved.</P>

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