Synthesis of Alkyl Silanes via Reaction of Unactivated Alkyl Chlorides and Triflates with Silyl Lithium Reagents

Abstract

The reaction of unactivated secondary and primary alkyl chlorides as well as primary alkyl triflates with silyl lithium reagents to access tetraorganosilanes is reported. These nucleophilic substitutions proceed in the absence of any transition metal catalyst under mild conditions in moderate to very good yields. The silyl lithium reagents are readily generated from the corresponding commercially available chlorosilanes. Enantioenriched secondary alkyl chlorides react with high stereospecificity under inversion of configuration.

Facile preparation of organosilanes from benzylboronates and gem-diborylalkanes mediated by KOtBu

“…4 Highly reactive organometallic species, including Grignard reagents, organolithiums, organozincs or ganoaluminiums, are emerging as the most attractive substrates for the construction of organosilanes. 5,6 Although these transformations are synthetically useful, these organometallic reagents exhibit a high basicity and strong nucleophilicity, making them incompatible with many functional groups. Organohalides are often used as precursors to organometallic reagents; therefore, substantial progress has been recently achieved to access silicon-containing molecules by cross-coupling from these abundant and structurally diverse feedstocks to replace preformed organometallic reagents.…”

Nickel(ii)-catalyzed reductive silylation of alkenyl methyl ethers for the synthesis of alkyl silanes

“… 6 Recently, instead of noble metal catalysts, several kinds of base metal catalysts such as Fe, Co, Ni, and Mn have been developed for this transformation, generally with elegant catalyst design. 7 Other means including carbene insertion into silanes, 8 cross-coupling with organosilicon reagents, 9 or direct C(sp 3 )–H silylation 10 all contribute to provide alkyl silanes.…”

Nickelkatalysierte, reduktive C(sp3)‐Si‐Kreuzkupplung von α‐cyanosubstituierten Alkylelektrophilen und Chlorsilanen

“…So sind beispielsweise asymmetrische Varianten derzeit auf kupferkatalysierte, S N 2-artige Reaktionen von aktivierten Alkylelektrophilen mit borbasierten Siliciumpronukleophilen [4] oder unkatalysierte Substitutionsreaktionen nichtaktivierter Alkylelektrophile mit metallierten Siliciumreagenzien beschränkt. [6] Eine weitere offene Aufgabe ist die Zusammenführung von Kohlenstoff-und Siliciumelektrophilen in reduktiven Kupplungsreaktionen, welche keiner vorgeschalteten Metallierung eines der beiden Kupplungspartner bedürfen. Im vergangenen Jahr beschrieben Shu und Mitarbeiter einen solchen reduktiven Prozess für die C(sp 2 )-Si-Bindungsknüpfung ausgehend von Vinyl-und Aryltriflaten/-halogeniden (Schema 1, unten).…”