Defluorosilylation of Industrially Relevant Fluoroolefins Using Nucleophilic Silicon Reagents

Abstract

A number of new magnesium and lithium silyl reagents were prepared and shown to be outstanding nucleophiles in reactions with industrially relevant fluoroolefins. These reactions result in a net transformation of either sp 2 or sp 3 C-F bonds into C-Si bonds by two modes of nucleophilic attack (SNV or SN2'). The methods are mild, proceeding with high chemo-and regioselectivity. Mechanistic pathways are described that lead to new substitution patterns from HFO-1234yf, HFO-1234ze and HFO-1336mzz, previously inaccessible by transition metal catalysed defluorosilylation routes.

Photoredox Defluorinative Silylation of α-Trifluoromethyl Arylalkenes Using Silacarboxylic Acids as Silyl Radical Precursors

“…Among the various methods reported, defluorinative silylation of α-trifluoromethyl alkenes is one of the most straightforward strategies for the construction of α-silylated gem -difluoroalkenes. 6 For example, allyllithiums, 6b silylmagnesiums, 6b and silylboronates 6c successfully undergo defluorinative silylations with α-trifluoromethyl alkenes through an ionic process, yielding structurally diverse gem -difluoroalkenes (Figure 1b ). However, the application of these seminal methods is hindered by harsh reaction conditions as well as by the high cost and instability of the silyl species.…”

Transition‐Metal‐Free Defluorosilylation of Fluoroalkenes with Silylboronates

“…developed a base‐promoted defluorosilylation of unactivated fluoroarenes and fluoroalkanes by C—F bond cleavage . Despite these advances, transition‐metal‐free defluorosilylation of fluoroalkenes to build silylated fluoroalkenes remains elusive …”

Rhodium-catalyzed asymmetric hydroamination of gem-difluoroallenes with anilines

“…Gem-difluoroalkenes are essential structural motifs in medicinal design [1][2][3][4][5][6][7] and organic synthesis [8][9][10][11][12][13][14][15][16][17][18][19][20]. Among them, gemdifluoroallylic amine scaffolds bearing a chiral C-N bond have been examined for potential applications for isostere-based drug design and enzyme inhibitors (Figure 1a) [23][24][25][26][27].…”