Palladium(II)-Promoted Cyclization Reaction of 4-Hydroxybutyronitrile to 2-Iminotetrahydrofuran. X-ray Structure of cis-[PdCl2{N(H)CCH2CH2CH2O}- (PPh3)]·1/2CH2Cl2

Reaction of 3-bromo-1-propanol with Et 4 N(CN) in CH 2 Cl 2 at room temperature gives in high yield 4-hydroxybutyronitrile, HO(CH 2 ) 3 CN ( 1 ), which upon reaction with Na 2 PdCl 4 affords [PdCl 2 {N(H) CCH 2 CH 2 CH 2 O} 2 ] ( 2 ), containing two 2-iminotetrahydrofuran ligands derived from intramolecular cyclization of 1 . Substitution of one imino ligand for an entering nucleophile L leads to the complexes [PdCl 2 {N(H) CCH 2 CH 2 CH 2 O}(L)] (L = PPh 3 ( 3 ), py ( 4 ), DMF ( 5 )) . Similarly, the reaction of 2 with 1 equiv of cis -Ph 2 PCH CHPPh 2 results in the displacement of the two iminolactone ligands and formation of [PdCl 2 (Ph 2 PCH CHPPh 2 )]. The ligand 1 and the complexes 2 − 5 were characterized by analytical and spectroscopic techniques. IR data suggest that 2 and 3 are present as a mixture of cis and trans isomers, while 4 and 5 have a trans stereochemistry. Complex 3 gave crystals of the cis form, as evidenced by an X-ray structural determination.