Copper-Catalyzed Cross-Coupling of Aryldiazoacetates with Bis[(pinacolato)boryl]methane

The copper-catalyzed cross-coupling reaction of 1,1-bis[(pinacolato)boryl]methane with α-diazophenylacetate as carbene precursor was reported, leading to the construction of C(sp 3 )-C(sp 3 ) bond.Reaction optimization experiments showed that Monophos ligand was critical for the success of this reaction.In situ oxidation afforded the corresponding primary alcohols instead of the relatively unstable boronates.The reaction has high efficiency and good functional group compatibility.The two-step transformation represents a formal hydroxymethylation of diazoacetates.Keywords copper catalysis; C(sp 3 )-C(sp 3 ) bond formation; diazo compounds; bis[(pinacolato)boryl]methane Scheme 1 Cu(I) carbene migratory insertion with BpinCH2 Results and discussionTo test our hypothesis, tert-butyl 2-diazo-2-phenylacetate 1a was chosen as the model substrate to react with di-