Oxidative addition of methylene chloride to Me-DuPhos complexes of palladium and rhodium

Abstract

Oxidative addition of methylene chloride to Pd((R,R)-Me-DuPhos)(L) (1–3; L = P(t-Bu)3, PCy3, or trans-stilbene) gave Pd((R,R)-Me-DuPhos)(CH2Cl)(Cl) (4). Treatment of [Rh(COD)(Cl)]2 with (R,R)-Me-DuPhos at low temperature in THF or CH2Cl2 afforded [Rh((R,R)-Me-DuPhos)(Cl)]2 (5). At room temperature, these reactions also gave the byproduct [Rh((R,R)-Me-DuPhos)2][Cl], which was prepared independently as the BF4 salt 6. When 5 was generated in CH2Cl2, oxidative addition of both CCl bonds yielded the bridging carbene complex (Rh((R,R)-Me-DuPhos)(Cl))2(µ-Cl)2(µ-CH2) (8). Both 6 and 8 were crystallographically characterized.