TY - JOUR
T1 - Reductive dechlorination of aryl chlorides catalyzed by palladium complexes containing basic, chelating phosphines
AU - Ben-David, Yehoshua
AU - Gozin, Michael
AU - Portnoy, Moshe
AU - Milstein, David
PY - 1992
Y1 - 1992
N2 - Aryl chlorides undergo efficient, homogeneously catalyzed reductive dechlorination to the corresponding arenes using Pd(dippp)2 as catalyst [dippp=1,3-bis(diisopropylphosphino) propane], which may be generated in situ from Pd(OAc)2 and two equivalents of dippp. Two reducing systems are described: (a) sodium hydroxide in methanol; (b) sodium formate in alcohol or DMF. Base-sensitive functional groups (CHO, CN) do not survive the conditions of system (a), but remain unaffected during dechlorination with sodium formate. Various functional groups are tolerated, and high yields are obtained. The reaction rate is retarded by electron-donating substituents, indicating a rate-determining oxidative addition step. Reaction of the model complex (dippp)Pd(Ph)Cl with sodium formate in the presence of dippp leads to the formation of Pd(dippp)2 and benzene. Dippp homologues are also effective ligands in the catalytic reaction, the reactivity order being dippp > dippb > dippe. Iso-Pr3P is only marginally effective. A mechanistic interpretation of these observations is given.
AB - Aryl chlorides undergo efficient, homogeneously catalyzed reductive dechlorination to the corresponding arenes using Pd(dippp)2 as catalyst [dippp=1,3-bis(diisopropylphosphino) propane], which may be generated in situ from Pd(OAc)2 and two equivalents of dippp. Two reducing systems are described: (a) sodium hydroxide in methanol; (b) sodium formate in alcohol or DMF. Base-sensitive functional groups (CHO, CN) do not survive the conditions of system (a), but remain unaffected during dechlorination with sodium formate. Various functional groups are tolerated, and high yields are obtained. The reaction rate is retarded by electron-donating substituents, indicating a rate-determining oxidative addition step. Reaction of the model complex (dippp)Pd(Ph)Cl with sodium formate in the presence of dippp leads to the formation of Pd(dippp)2 and benzene. Dippp homologues are also effective ligands in the catalytic reaction, the reactivity order being dippp > dippb > dippe. Iso-Pr3P is only marginally effective. A mechanistic interpretation of these observations is given.
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U2 - 10.1016/0304-5102(92)80070-W
DO - 10.1016/0304-5102(92)80070-W
M3 - Article
AN - SCOPUS:0011919368
VL - 73
SP - 173
EP - 180
JO - Journal of Molecular Catalysis
JF - Journal of Molecular Catalysis
SN - 0304-5102
IS - 2
ER -