New approach to chiral phosphapalladacycles: first optically active phosphinite PC-palladacycle with non-metallocenic planar chirality

A new proposed methodology for the preparation of phosphapalladacycles in enantiopure form includes the use of the same optically active cyclopalladated CN-reagent for both resolution of a racemic ligand and subsequent direct C–H bond activation of the enantiopure ligand via the cyclopalladated ligand exchange reaction. This protocol was successfully employed for the preparation of the complex, which is both the first PC-palladacycle with a non-metallocenic planar chirality based on the [2.2]paracyclophane framework and the first representative of chiral phosphinite PC-palladacycles.

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(Rpl,Rpl)-Di-μ-chlorobis{4-diphenylphosphinoxy[2.2]paracyclophan-5-yl-C,P}dipalladium(II)C56H48Cl2O2P2Pd2Ee >98%[α]D24=+166 (c 0.68, CH2Cl2)Source of chirality: ligand resolution on (RC)-CN-palladacycleAbsolute configuration: (Rpl)

(Spl,RC)-Chloro{1-(1-aminoethyl)naphthyl-C,N}{4-diphenylphosphinoxyl[2.2]paracyclophane-P}palladium(II)C40H37ClNOPPdEe >98%[α]D24=+21.7 (c 1.20, CH2Cl2)Source of chirality: ligand resolution on (RC)-CN-palladacycleAbsolute configuration: (Spl,RC)

(Rpl,RC)-Di-μ-chlorobis{4-diphenylphosphinoxy[2.2]paracyclophan-5-yl-C,P}dipalladium(II)C40H37ClNOPPdEe >98%[α]D24=-36.7 (c 1.20, CH2Cl2)Source of chirality: ligand resolution on (RC)-CN-palladacycleAbsolute configuration: (Rpl,RC)

(Spl,SC,SN)-{4-Diphenylphosphinoxyl[2.2]paracyclophane-5-yl-P,C}(prolinate-N,O)palladium(II)C33H32NO3PPdEe >98%[α]D24=+244.7 (c 0.47, CH2Cl2)Source of chirality: ligand resolution on (RC)-CN-palladacycleAbsolute configuration: (Spl,SC,SN)