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Allyltrichlorosilane is an organosilicon compound with the formula Cl 3 SiCH 2 CH=CH 2.It is a colorless or white low-melting solid. [1] It was originally prepared by the Direct process, the reaction of allyl chloride with copper-silicon alloy.
Allylation is the attachment of an allyl group to a substrate, usually another organic compound. Classically, allylation involves the reaction of a carbanion with allyl chloride. Alternatives include carbonyl allylation with allylmetallic reagents, such as allyltrimethylsilane, [9] [10] [11] or the iridium-catalyzed Krische allylation.
First, the palladium coordinates to the alkene, forming a η 2 π-allyl-Pd 0 Π complex. The next step is oxidative addition in which the leaving group is expelled with inversion of configuration and a η 3 π-allyl-Pd II is created (also called ionization). The nucleophile then adds to the allyl group regenerating the η 2 π-allyl-Pd 0 complex.
Carbonyl allylation has been employed in the synthesis of polyketide natural products and other oxygenated molecules with a contiguous array of stereocenters. For example, allylstannanation of a threose-derived aldehyde affords the macrolide antascomicin B, which structurally resembles FK506 and rapamycin, and is a potent binder of FKBP12. [12]
Organostannane addition reactions comprise the nucleophilic addition of an allyl-, allenyl-, or propargylstannane to an aldehyde, imine, or, in rare cases, a ketone. [1] The reaction is widely used for carbonyl allylation.
Silicon tetrachloride and trichlorosilane are intermediates in the production of ultrapure silicon in the semiconductor industry. Chlorosilanes obtained from crude silicon are purified by fractional distillation techniques and then reduced with hydrogen to give silicon of 99.999 999 999 % purity.
The Krische allylation involves “transfer hydrogenative” carbon-carbon bond formations. [16] In a series of papers published in the early 2000s, Krische and coworkers demonstrated that allenes, dienes, and allyl acetates could be converted to transient allylmetal nucleophiles via hydrogenation, transfer hydrogenation or hydrogen auto-transfer. [17]
The Carroll rearrangement is an adaptation of the Claisen rearrangement and effectively a decarboxylative allylation. The Carroll rearrangement (1940) in the presence of base and with high reaction temperature (path A ) takes place through an intermediate enol which then rearranges in a sigmatropic Claisen rearrangement.