Aromatic deoxygenative allylation

Deoxygenative allylation of aromatic ketones can be performed by the InCI (-catalyzcd reaction with HSiMe2Cl and 10 (Equation (17)).85... 

A combination of chlorodimethylsilane and allyltrimethylsilane effectively promotes the deoxygenative allylation of aromatic ketones to terminal alkenes in the presence of a catalytic amount of InCl3 (Equation (94)). The choice of solvent is important the reaction of acetophenone proceeds only in dichloromethane or 1,2-dichloroethane. Aldehydes and aliphatic ketones give complicated mixtures. 

In the presence of excess acetyl halide and a tin(II) catalyst aromatic acetals react with allyltrimethylsilane to give a-allylbenzyl halides in good yield by double substitution of the acetal alkoxy groups (Scheme 10.127) [365]. The indium-catalyzed tandem reaction using a hydrosilane-allylsilane system enables deoxygenative allylation of aromatic ketones [366]. 

Reaction with Allylic Halides, Alcohols, and their Derivatives. Allylation of allyl and propargyl trimethylsilyl ethers as well as benzyl and propargylic alcohol derivatives proceeds in the presence of a catalytic amount of Lewis acids, such as ZnC, TMS(OTf), and B(C6F5)3. Direct substitutions of the hydroxyl group of allylic, ben-zylic, and propargylic alcohols are catalyzed by HN(S02F)2, a rhenium-oxo complex, and InCls (eq 27). A combination of chlorodimethylsilane and allyltrimethylsilane effectively promotes the deoxygenative allylation of aromatic ketones in the presence of a catalytic amount of an indium compound, such as indium trihalide or metallic indium (eq 28). Allylation of cyclic allylic acetates with allyltrimethylsilane can be catalyzed by molecular iodine. ... 

Carbonyl reduction begins to compete with olefin saturation when the double bond is hindered or the carbonyl is aromatic or an aromatic vinylog. In conjugated systems, deoxygenation may occur via an intermediate allylic alcohol (51). 

Phenols are transformed into aryl chlorides by PhPCl4779. Aromatic and aliphatic aldehydes give, in high yields, gem dibromides with combination of triphenylphosphite and bromine780. Brominative deoxygenation of ketones is achieved by 2,2,2-tribromo-l,2,3-benzodioxaphosphone781. Allylic alcohols are transformed into allylic iodides by reaction with P2I4782. 

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