Mono‐ or bidentate boron Lewis acids trigger a regioselective magnesiation or zincation of pyridazine in position C3 (ortho product) or C4 (meta product). The regioselectivity of the metalation was rationalized with the help of calculated pKa values of both pyridazine and pyridazine/Lewis acid complexes.

Ein-oder zweizähnige Lewis-Säuren leiten eine regioselektive Magnesierung oder Zinkierung an Pyridazin in Position C3 (ortho-Produkt) oder C4 (meta-Produkt) ein. Die Regioselektivitätd er Metallierung wurde mithilfe der berechneten pK s -Werte von sowohl Pyridazin als auchden Pyridazin-Lewis-Säure-Komplexen erklärt.

Aryl- and heteroaryl-dichlorophosphines are mildly and selectively made in a one-pot synthesis in moderate to good yields starting from the respective aryl bromides or five-membered heterocycles, following lithiation with nBuLi, transmetalation with ZnCl2, and subsequently the reaction with PCl3. Selected aryl- and heteroaryl-dichlorophosphines were successfully synthesized using this reaction method and could easily be purified after isolation. The intermediate formation of the organozinc species is essential, as it prevents the formation of multiple substitution products. Important are also the reaction conditions: the usage of the proper solvent for the respective aromatic precursors and removal of the remaining salts by addition of a dioxane/pentane mixture. Depending on the solvent and steric demand of the substituent, mono- and bis-substitution products can be formed but formation also prevented. Hereby, different organozinc species might play an important role.