Breaking Carbon–Fluorine Bonds with Main Group Nucleophiles

Abstract

In this Account we describe a series of new reactions that we, and others, have reported that involve the transformation of C–F bonds into C–Mg, C–Al, C–Si, C–Fe and C–Zn bonds. We focus on the use of highly reactive main group nucleophiles and discuss aspects of reaction scope, selectivity and mechanism.1 Introduction1.1 The Fluorocarbon Industry and Sustainability1.2 Production of Fluorocarbons1.3 Properties of Fluorocarbons1.4 Our Work2 Results and Discussion2.1 Low-Valent Main Group Compounds2.1.1 Reactions with Fluoroarenes2.1.2 Reactions with Fluoroalkanes2.1.3 Reactions with Fluoroalkenes2.2 Main Group Nucleophiles (M1–M2)2.2.1 Reactions of M1–M2 Nucleophiles with Fluoroarenes2.2.2 Reactions of M1–M2 Nucleophiles with Fluoroalkanes2.2.3 Reactions of M1–M2 Nucleophiles with Fluoroalkenes3 Summary and Perspective

Stereoselective Palladium‐Catalyzed C−F Bond Alkynylation of Tetrasubstituted gem‐Difluoroalkenes

“…Activation of the carbon-fluorine bond constitutes an important area of research in modern organofluorine chemistry. [1] In contrast to C À F bond formation, [2] selective cleavage and functionalization of robust C À F bonds in abundant polyor perfluorinated compounds offers new opportunities for the synthesis of value-added fluorinated molecules. [3] For instance, selective transformation of one CÀF bond of gemdifluoroalkenes [4] leads to functionalized monofluoroalkenes.…”

Defluorosilylation of trifluoromethane: upgrading an environmentally damaging fluorocarbon

“…Despite being widely employed as refrigerants, hydrofluorocarbons (HFCs) are potent greenhouse gases and important contributors to global warming. 1,2 The threat posed by HFCs was highlighted by a recent amendment to the Montreal Protocol seeking to reduce HFCs by 480% by 2050. 3 Trifluoromethane (HCF 3 , HFC-23) has a global warming potential 11 700 times greater than CO 2 , and an atmospheric lifetime of 264 years.…”

“…Much progress has been made in the field of upgrading fluorocarbons into reactive building blocks, particularly with the use of nucleophilic main group reagents. 1,14,15 Fluoroalkanes remain the least reactive substrates due to high sp 3 C-F bond dissociation energies and a lack of charge stabilisation in the bond-breaking transition state. 1,16 Despite this, our group has in recent years demonstrated the C-F activation of simple fluoroalkanes using aluminium and magnesium nucleophiles.…”

“…1,14,15 Fluoroalkanes remain the least reactive substrates due to high sp 3 C-F bond dissociation energies and a lack of charge stabilisation in the bond-breaking transition state. 1,16 Despite this, our group has in recent years demonstrated the C-F activation of simple fluoroalkanes using aluminium and magnesium nucleophiles. 17,18 Furthermore, the groups of Shibata and Martin have both reported C-F activation of a range of fluoroalkanes using group 1 metal silyl nucleophiles.…”

“…This methodology offers the potential to recycle a highly abundant, low-value fluorocarbon, minimising waste and environmental damage, to create a pharmaceutically relevant building block of high-value. 1 Trifluoromethane (1 bar, 22 1C) was added to a C 6 D 6 solution of the silyl lithium reagent PhMe 2 SiLiÁPMDETA (1ÁPMDETA) (PMDETA = pentamethyldiethylenetriamine), and the building block PhMe 2 SiCF 2 H (2) was formed in a 90% spectroscopic yield (Fig. 2).…”