Allyl carbamates palladium catalysis

Reaction with Alkyl Halides. The Grignard reagent (1) can be alkylated by allyl halides to afford the homoallylsilane. The use of a nickel(II) catalyst facilitates coupling of the Grignard reagent (1) to vinyl halides and aryl halides, triflates and O-carbamates and provides a useful method for the preparation of allyl- andbenzylsilanes (eq 7). Palladium catalysis is also effective to couple (1) with vinyl halides. 

Palladium(II) catalysis (0.01-0.04 equiv) is more effective and leads to higher selectivity than mercury(II) catalysis912. With bis(acetonitrile)palladium(II) chloride [Pd(CH3CN)2CI2] as catalyst the efficiency decreases in the order carbamates > allylic acetates > carbonates. 

Three types of simple 0-nucleophiles have been reported to react with allyl carbonates under Pd catalysis (Scheme 32, Table 3) carboxylatesP and carbamic acid conjugate base,P phenols,P p p and alcohols.As previously stated allylation of nucleophiles with allylic carbonates can be performed in the absence of base, and the total amount of real nucleophile present at any moment in the reaction medium cannot be higher than the amount of palladium added. However, in asymmetric reactions it is sometimes... 

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