Allylgallium reagents

Ga. Gallium was used to mediate the allylation of carbonyl compounds in water.170 The reaction can also be carried out by using preformed allylgallium reagents.171 The corresponding homoallyl alcohols were obtained in high yields without the assistance of either acidic media or sonication (Eq. 8.72). 

Homoallylic hydroxylamines and homoallylic hydrazines are synthesized in excellent yields from aldonitrones and hydrazones in aqueous media with allylgallium reagent in the presence of O.lequiv. of NH4G1 or Bu4NBr. The reaction rate can be increased dramatically under microwave activation (Scheme 129).416... 

Triorganogallium and -indium reagents react with a,/3-unsaturated nitrile, ketone, and ester to give 1,4-addition products regioselectively (Table 31). In contrast, the reaction of allylgallium and allylindium sesquihalides with a,/3-unsaturated carbonyl compounds proceed in a 1,2-addition mode, whereas 1,4-addition takes place with a,/3-unsaturated nitriles.294... 

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