Alkali Metal-Hydroxide-Catalyzed C(sp)–H Bond silylation

Abstract

Disclosed is a mild, scalable, and chemoselective catalytic cross-dehydrogenative C-H bond functionalization protocol for the construction of C(sp)-Si bonds in a single step. The scope of the alkyne and hydrosilane partners is substantial, providing an entry point into various organosilane building blocks and additionally enabling the discovery of a number of novel synthetic strategies. Remarkably, the optimal catalysts are NaOH and KOH.

KOtBu‐Catalyzed Michael Addition Reactions Under Mild and Solvent‐Free Conditions

“…Encouraged by recent reports of impressive catalysis using KO t Bu, at the outset, reaction of 1‐hexanol (1 mmol) and acrylonitrile (1 mmol) with various bases (using 1 mol %) were screened, which revealed the superior catalysis by KO t Bu over the other alkali metal salts (Table ). GC analysis of the reaction mixture shows complete conversion within 20 minutes and the product was isolated in 98 % (Table , entry 8).…”

“…Encouraged by recentr eports of impressive catalysis using KO t Bu, [40][41][42][43] at the outset, reaction of 1-hexanol (1 mmol) and acrylonitrile (1 mmol) with various bases (using 1mol %) were screened, which revealed the superiorc atalysis by KO t Bu over the other alkali metal salts ( Using the optimized reaction condition, Michael addition of assortmento fn ucleophilesw itha crylonitrile was investigated (Scheme2,3 ). Unactivated aliphatic linear chain alcohols such as methanol,e thanol, 1-butanol, 1-hexanol and 1-nonanol, and aliphatic alcohols containing olefin, fluoro and cyclic ether functionalities provided complete conversion with excellent yields of products 3a-3j,r espectively.C yclic amine, heteroaryl and arene functionalized primary alcohols and secondary alcohols such as isopropanol, menthol, 1-phenylethanol, 2,3-dihydro-1H-inden-2-ola nd cholesterol were examined using 1mol %o fK O t Bu, which provided products 3k-3r in very good yields.…”

“…Thus, development of operationally simple, additive free, solvent free and simple catalytic system devoid of designed precious metal catalysts can be highly beneficial. Catalysis by alkali metal salts is gaining importance very recently . Herein, we report an inexpensive, highly abundant and commercially available potassium tert ‐butoxide (KO t Bu) catalyzed Michael addition reactions.…”

“…Catalysis by alkali metal salts is gaining importance very recently. [40][41][42][43] Herein, we report an inexpensive, highly abundant and commerciallya vailable potassium tert-butoxide (KO t Bu) catalyzed Michael addition reactions. Particularly,t his catalytic protocol is compatible with a wide range of heteroatom nucleophiless uch as alcohols (both aliphatic and aromatic primary and secondary alcohols),t hiols and amines with acrylonitrile, substituted acrylonitriles, acrylamide and acrylic esters.…”

Tuning the Selectivity of AuPd Nanoalloys towards Selective Dehydrogenative Alkyne Silylation

“…Pukhnarevich and co‐workers disclosed the first transition‐metal‐catalyzed coupling of alkynes and hydrosilanes by using H 2 PtCl 6 in the presence of iodine to give the corresponding alkynylsilanes . Since this work, other homogeneous transition‐metal catalysts,– as well as strong bases or reducing agents, such as alkoxides, Na/HMPT, MgO, NaOH, LiAlH 4 ,, KNH 2 /Al 2 O 3 and NaHBEt 3 have been shown to mediate this transformation. Recently, Ma et al.…”