Volume 54, Issue 21 pp. 6315-6319
Communication

Umpolung of Methylenephosphonium Ions in Their Manganese Half-Sandwich Complexes and Application to the Synthesis of Chiral Phosphorus-Containing Ligand Scaffolds

Dr. Dmitry A. Valyaev

Corresponding Author

Dr. Dmitry A. Valyaev

Laboratoire de Chimie de Coordination du CNRS (UPR 8241), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) http://www.lcc-toulouse.fr/lcc/spip.php?article24

Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France)

Laboratoire de Chimie de Coordination du CNRS (UPR 8241), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) http://www.lcc-toulouse.fr/lcc/spip.php?article24Search for more papers by this author
Dr. Oleg A. Filippov

Dr. Oleg A. Filippov

A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences, 28 Vavilov Street, GSP-1, B-334, Moscow (Russia)

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Dr. Noël Lugan

Corresponding Author

Dr. Noël Lugan

Laboratoire de Chimie de Coordination du CNRS (UPR 8241), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) http://www.lcc-toulouse.fr/lcc/spip.php?article24

Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France)

Laboratoire de Chimie de Coordination du CNRS (UPR 8241), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) http://www.lcc-toulouse.fr/lcc/spip.php?article24Search for more papers by this author
Dr. Guy Lavigne

Dr. Guy Lavigne

Laboratoire de Chimie de Coordination du CNRS (UPR 8241), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) http://www.lcc-toulouse.fr/lcc/spip.php?article24

Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France)

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Prof. Dr. Nikolai A. Ustynyuk

Prof. Dr. Nikolai A. Ustynyuk

A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences, 28 Vavilov Street, GSP-1, B-334, Moscow (Russia)

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First published: 01 April 2015
Citations: 31

Financial support from the CNRS and the PICS grant 4873 (CNRS)/09-03-91060 (RFBR) is gratefully acknowledged. O.A.F. is grateful to the Russian Scientific Foundation (grant 14-13-00801) for financial support of DFT calculations. D.A.V. thanks the IDEX-UNITI for a starting grant.

Graphical Abstract

Reactivity trend reversal: Methylenephosphonium salts coordinated to a manganese center were found to exhibit “iminium-like” reactivity towards nucleophiles (see scheme). This unprecedented umpolung enables the instant formation of carbon–heteroatom bonds, highlighted by the synthesis of novel chiral pincer-type phosphine–NHC–phosphine ligands.

Abstract

Half-sandwich manganese methylenephosphonium complexes [Cp(CO)2Mn(η2-R2PC(H)Ph)]BF4 were obtained in high yield through a straightforward reaction sequence involving a classical Fischer-type manganese complex and a secondary phosphine as key starting materials. The addition of various nucleophiles (Nu) to these species took place regioselectively at the double-bonded carbon center of the coordinated methylenephosphonium ligand R2P+C(H)Ph to produce the corresponding chiral phosphine complexes [Cp(CO)2Mn(κ1-R2PC(H)(Ph)Nu)], from which the phosphines were ultimately recovered as free entities upon simple irradiation with visible light. The synthetic potential of this umpolung approach is illustrated herein by the preparation of novel chiral pincer-type phosphine–NHC–phosphine ligand architectures.

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