Allyl organometallic compounds 3 + 2 cycloaddition reactions

The intramolecular [4+3] cycloaddition reaction towards seven-membered rings involving furans and allylic cations have been reviewed <01ACR595>. A review on the use of 2-siloxyfurans as butenolide precursors has appeared <01T3221>. Organometallic compounds of furans and their benzoannulated derivatives have also been summarized <01 AHCI>. 

Complexes of iron and other metals which are prepared from a allyl or propargyl organometallic compounds and (NC)2C = C(CN)2, SO2, or related unsaturated electrophilic molecules via cycloaddition reactions are important because such complexes may find application in organic synthesis " ... 

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