Synthesis of Borylated Hydrazino Acid Derivatives

α-Boryl-α-hydrazinoacetic acid is a highly functionalized boron-containing building block that can be easily accessed from readily available α-borylacetaldehyde. The hydrazine motif can be converted into a variety of α-borylated azoles and diazines in a straightforward protocol. Furthermore, the carboxy group can be derivatized to afford novel organoboron compounds that should find applications in various cross-coupling transformations.