Allylzirconocene chlorides

Allylzirconation of alkynes with allylzirconocene chloride reagents (obtained by hydrozir-conation of allenes) takes place in the presence of a catalytic amount of methylaluminox-ane (MAO) [67,68]. MAO presumably abstracts chloride to form an allylzirconocene cation, which coordinates to the alkyne triple bond. The subsequent migratory insertion is regioselective, as it is found that the new bond is mainly formed between the a-carbon of the allylzirconium species and the internal carbon of a terminal alkyne (Scheme 8.33). 

Allylzirconocene chlorides. These re l-alken-4-ols by reaction with aldehydes h derived from allenylstannanes condense i... 

Allylzirconocene chlorides. These reagents are formed from allenes. A route to l-alken-4-ols by reaction with aldehydes has been developed. 1,1-Bimetallic species derived from allenylstannanes condense with aldehydes to form 1,3-dienes. ... 

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