Reactions with allylboronates reduction

The addition of allylboronates 1 to the chiral oxime 2 results in the formation of a hydroxyl-amine. This is a general method for the subsequent reductive generation of primary homoallyl-amines, but with poor diastereoselectivity in the case of 3 and 4. A diastereomeric ratio of 90 10 is achieved in the addition reaction, using the chiral allylboronate 59 (double stcrcodifferenti-ation). 

The following reactions proceed with the participation of the allylic boron system (i) allylboration and protolytic cleavage of organic compounds with multiple bonds, (ii) allylboron-alkyne condensation,598 599 (iii) reductive mono-and trans-a,a -diallylation of nitrogen aromatic compounds, (iv) disproportionation processes between tribut-2-enylborane and BX3 (X = C1, Br, OR, SR). Allylboration of carbonyl compounds, thioketones, imines, or nitriles leads to the homoallylic alcohols, thiols, or amines (Equations (136) and (137). It is most important that 1,2-addition to aldehydes and imines proceeds with high diastereoselectivity so that ( )-allylic boranes and boronates give the anti-products, while -products are formed preferentially from (Z)-isomers. 

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