Tris(pentafluorophenyl)borane-Catalyzed Reactions Using Silanes

Abstract

The utility of an electron-deficient, air stable, and commercially available Lewis acid tris(pentafluorophenyl)borane has recently been comprehensively explored. While being as reactive as its distant cousin boron trichloride, it has been shown to be much more stable and capable of catalyzing a variety of powerful transformations, even in the presence of water. The focus of this review will be to highlight those catalytic reactions that utilize a silane as a stoichiometric reductant in conjunction with tris(pentafluorophenyl) borane in the reduction of alcohols, carbonyls, or carbonyl-like derivatives.

Challenges in the Electrochemical Synthesis of Si2Cl6 Starting from Tetrachlorosilane and Trichlorosilane

“…[34,35] By CV measurements the evidence for an activation of SiÀ H bond in presence of perchlorate anion is not clear. Adduct formation without hydride abstraction by B(C 6 F 5 ) 3 elongates the SiÀ H bond, [36] and should shift the oxidation potential to less anodic values due to decreasing activation barrier for SiÀ H cleavage. For the borohydride stabilized silyl cation an oxidation peak for [HB(C 6 F 5 ) 3 ] À at about 0.88 V vs. FcH/FcH + was reported by Wildgoose and co-workers.…”

Efficient Conversion of Biomass Derived Levulinic Acid to γ‐Valerolactone Using Hydrosilylation

“…B(C 6 F 5 ) 3 has been used for hydrosilylation, deoxygenation, borylation, polymerization and hydrogenation among others, [19] and is relatively stable even in the presence of water. The catalytic system of B(C 6 F 5 ) 3 and silanes has been utilized multiple times for many interesting transformations, and we were curious to explore its reactivity towards levulinic acid.…”

Nitrenium Salts in Lewis Acid Catalysis

“…[40,41] Generally, moving away from metal-based systems to main group catalysts reduces operational costs,particularly when separation of the catalyst from the product is necessary.Perhaps the most widely employed system in this category is tris(pentafluorophenylborane) [B(C 6 F 5 ) 3 ;B CF] due to its high Lewis acidity and ubiquitous use in frustrated Lewis pair (FLP) chemistry. [42][43][44][45] It is worth noting however, that catalytic reactions employing BCF are often performed under inert conditions given its propensity to form as table adduct with water and undergo further hydrolysis at elevated temperatures. [45][46][47] Herein, we prepared the nitrenium salts 1 and 2 (Scheme 1), and probed their Lewis acidity in an effort to benchmark them relative to more conventional Lewis acids.…”