Direct preparation of copper organometallics bearing an aldehyde function

• Chem. Commun., 2006, 2486-2488
• DOI: 10.1039/b604259g

Polyfunctionalized organometallics are versatile intermediates in modern organic chemistry, since they allow the formation of multifunctional products.¹ One of the best preparation methods of these organometallic reagents is the halogen–metal exchange reaction.^1e,2 The halogen–magnesium³ and halogen–copper⁴ exchanges have recently been extensively investigated. They allow the convenient preparation of polyfunctional aryl, heteroaryl and alkenyl organometallic reagents that bear various functional groups. The formyl group is present in numerous compounds, but has been regarded as being incompatible with most organometallic reagents.⁵ Only scarce examples of formyl-substituted aryl organometallic compounds have been reported.⁶ In most cases, tedious protection and deprotection steps or an additional oxidation step are required to introduce this sensitive function in a target molecule.

Iodine–copper exchange reaction allows the direct preparation of various new aryl, heteroaryl and alkenyl cuprates bearing an aldehyde group, thus expanding the applications of functionalized copper organometallic species in organic synthesis.