Synthesis and application of benzyl-TMS derivatives as bench stable benzyl anion equivalents

Palladium-Catalyzed Cross-Coupling of Monochlorosilanes and Grignard Reagents

“…26 a-Trimethylsilylmagnesium chloride was effective at generating disilylmethane 7 , a highly useful class of carbon pronucleophiles for Peterson olefination and related reactions. 27,27c, 28 Sterically hindered neopentylsilanes 8 and 9 were also successfully synthesized even when utilizing the less active alkylmagnesium chloride reagents ( 9 ). 29 …”

Metal‐Catalyzed Dealkoxylative CarylC Cross‐Coupling—Replacement of Aromatic Methoxy Groups of Aryl Ethers by Employing a Functionalized Nucleophile

“…Thus, we decided to target ArCH 2 SiMe 3 products since they are stable and offer various options for subsequent transformations (Scheme 2) and are at the same time inert towards common cross-coupling catalysts. [13][14][15][16][17][18][19][20] With these considerations in mind we began to evaluate MCH 2 SiMe 3 nucleophiles in the presence of readily available nickel catalysts. Grignard reagents of the XMgCH 2 SiMe 3 type showed reduced reactivity because of the trimethylsilane (TMS) functionality.…”

“…The resulting stable ArCH 2 SiMe 3 products can readily be transformed into various products by Peterson olefination, [17] a fluoride-mediated mechanism, [13] photocatalysis, [14] gold catalysis, [15] or to the corresponding acyl silane by oxidation (Scheme 2). [18,19] Whereas a silicon-mediated a-anion stabilization at the CH 2 group is utilized for the deprotonation/ addition/elimination sequence in the Peterson olefination reaction, the silicon atom can also be useful for fluoridemediated reactions (with TBAF and TBAT) that lead to an active anion.…”

“…To demonstrate the utility of our reaction, we converted the ArCH 2 SiMe 3 substrates [13b, 18, 25] into the corresponding products 4-7 [13,[17][18][19]26] thereby also developing a new method for the preparation of 1-aryl-1-trifluoromethyl-2-aryl alkenes such as 8 (Scheme 3). Other important substrate classes that are directly accessible from our substrates include olefins, [17] various alcohols [13b] and amines [13a] in the b-position to the aryl group, diols, [16] and aromatic carboxylic acids [15] (Scheme 2).…”

Metallkatalysierte desalkoxylierende CAr‐C‐Kreuzkupplung – Austausch aromatischer Methoxygruppen von Arylethern unter Verwendung eines funktionalisierten Nukleophils

“…Unsere Aufmerksamkeit fiel auf ArCH 2 SiMe 3 -Verbindungen, die stabil sind, zahlreiche Mçglichkeiten für anschließende Transformationen bieten (Schema 2) und gleichzeitig inert gegenüber üblichen Kreuzkupplungskatalysatoren sind. [13][14][15][16][17][18][19][20] Mit diesen Überlegungen begannen wir, MCH 2 SiMe 3 -Nukleophile in Gegenwart handelsüblicher Ni-Katalysatoren zu testen. Grignard-Reagentien vom Typ XMgCH 2 SiMe 3 sind durch die Trimethylsilanfunktion in ihrer Reaktivität herabgesetzt.…”