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Sequential catalysis: exploiting a single rhodium(i) catalyst to promote an alkyne hydroacylation–aryl boronic acid conjugate addition sequence

We demonstrate that a single Rh(i) complex can promote two mechanistically distinct C–C bond-forming reactions – alkyne hydroacylation and aryl boronic acid conjugate addition – to deliver substituted ketone products from the controlled assembly of three readily available fragments. This is a rare e...

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Detalles Bibliográficos
Autores principales: Fernández, Maitane, Castaing, Matthias, Willis, Michael C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5351800/
https://www.ncbi.nlm.nih.gov/pubmed/28451201
http://dx.doi.org/10.1039/c6sc03066a
Descripción
Sumario:We demonstrate that a single Rh(i) complex can promote two mechanistically distinct C–C bond-forming reactions – alkyne hydroacylation and aryl boronic acid conjugate addition – to deliver substituted ketone products from the controlled assembly of three readily available fragments. This is a rare example of a Rh(i)/Rh(iii) cycle and a redox neutral Rh(i) cycle being promoted by a single catalyst. The process is broad in scope, allowing significant variation of all three reaction components. Incorporation of an enantiomerically pure bis-phosphine ligand renders the process enantioselective. Superior levels of enantioselectivity (up to >99% ee) can be achieved from using a two catalyst system, whereby two Rh(i) complexes, one incorporating an achiral bis-phosphine ligand and the second a chiral diene ligand, are introduced at the start of the reaction sequence.