- A Ligand-Free Pt3Cluster Catalyzes the Markovnikov Hydrosilylation of Alkynes with up to 106Turnover Frequencies
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The Pt-catalyzed hydrosilylation of alkynes is the procedure of choice to obtain vinylsilanes, and is claimed to be the most relevant application of Pt in organic synthesis. More than half a century after its discovery, only β-vinylsilanes (anti-Markovnikov addition) are obtained with simple Pt catalysts, whereas α-vinylsilanes (Markovnikov addition) remain elusive compounds. Here the catalysis of the Markovnikov hydrosilylation of terminal alkynes by Pt3clusters, in parts-per-million amounts, to give a wide variety of α-vinylsilanes in reasonable isolated yields and with turnover frequencies that can reach up to one million per hour is reported. Moreover, these α-vinylsilanes are reactive in well-stablished C?C bond-forming cascade reactions, in which the corresponding β-isomers are unreactive. Besides its efficiency and synthetic usefulness, this catalytic system is an excellent example of how the atom-by-atom aggregation of a catalytic metal leads to a different selectivity for a given reaction.
- Rivero-Crespo, Miguel A.,Leyva-Pérez, Antonio,Corma, Avelino
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p. 1702 - 1708
(2017/02/10)
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- Preparation of vinyl silyl ethers and disiloxanes via the silyl-heck reaction of silyl ditriflates
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Vinyl silyl ethers and disiloxanes can now be prepared from aryl-substituted alkenes and related substrates using a silyl-Heck reaction. The reaction employs a commercially available catalyst system and mild conditions. This work represents a highly practical means of accessing diverse classes of vinyl silyl ether substrates in an efficient and direct manner with complete regiomeric and geometric selectivity.
- Martin, Sara E. S.,Watson, Donald A.
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supporting information
p. 13330 - 13333
(2013/09/24)
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