Radical Frustrated Lewis Pairs

Chapter
Part of the Topics in Current Chemistry book series (TOPCURRCHEM, volume 334)

Abstract

While a growing body of literature describes FLP adducts of diamagnetic unsaturated substrates such as alkenes, alkynes and heterocumulenes such as carbon dioxide, capture of the diatomic radical nitric oxide (NO) by intramolecular phosphane/borane FLPs gives a new family of radical frustrated Lewis pair adducts. Capture of NO results in heterocycles with new P-N and B-N bonds featuring a spin density Umpolung of NO to give FLP-NO species that possess significant O-centered radical reactivity. Use of these radical FLP-NO species in C-H functionalization chemistry via H-atom abstraction / radical recombination sequences as well as deployment in nitroxide mediated polymerization of alkenes indicates a rich and diverse chemistry for FLP-NO species. An alternative, complementary strategy to generate radical FLPs involves the use of transition metal centers with unpaired electrons as the Lewis acid component of an FLP in conjunction with a tethered but hindered Lewis base.

Keywords

C-H functionalization Frustrated Lewis pairs Nitric oxide Nitroxides Nitroxide mediated polymerization Radicals 

Notes

Acknowledgments

The authors warmly thank their coworkers and collaborating research groups for their valuable contributions to the work described in this article. T.H.W is grateful to the US National Science Foundation (CHE-0840453 and CHE-0957606) as well as the Petroleum Research Fund (51971-ND3) for financial support. G.E. thanks the Deutsche Forschungsgemeinschaft, the Fond der Chemischen Industrie, the Alexander von Humboldt-Stiftung and the European Research Council for financial support.

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© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Department of ChemistryGeorgetown UniversityWashington, DCUSA
  2. 2.Organisch-Chemisches InstitutWestfälische Wilhelms-Universität MünsterMünsterGermany

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