Copper Grignard-derived functionalized

Remarkably, halogen-magnesium exchange can also be extended to aryl and heteroaryl bromides [24, 25], Thus, the functionalized aryl bromides 28 and 29 (Scheme 2.7) were converted, at 0 °C and at —30 °C, respectively, into the corresponding Grignard reagents. After treatment with CuCN, the copper derivative 30 and 31 were obtained. Subsequent treatment with typical electrophiles such as benzoyl bromide or allyl bromide furnished the products 32 and 33, in 70 and 80% yields. 

On the other hand, a transmetallation of Grignard reagent 69 to the corresponding copper derivative with CuCN-2LiCl [49] leads to the formation of the diamino derivative 297 in 65% yield (Scheme 4.62). Besides this, several other reagents are known that allow the formal oxidation of a Grignard reagent to an amino function and their use has been excellently reviewed elsewhere [144]. 

---