Allyl phosphine complexes of palladium and their use in catalysis
The present invention provides a palladium(II) complex of formula (1) or a palladium(II) complex of formula (2). R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 and R 24 , m, E and X are described in the specification. The invention also provides a process for the preparation of the complexes, and their use in carbon-carbon and carbon-heteroatom coupling reactions.
1. A palladium complex of formula (2):
wherein:
R 18 and R 19 are, independently, -Me, -Et, - n Pr, — i Pr, - n Bu, - i Bu, cyclohexyl, or cycloheptyl;
R 12 is an optionally substituted straight-chain C 1-20 alkyl, optionally substituted branched-chain C 3-20 alkyl, optionally substituted C 3-20 cycloalkyl, optionally substituted C 6-20 aryl, or optionally substituted heteroaryl having 1-20 carbon atoms;
R 20 and R 21 are both hydrogen;
R 22 , R 23 , and R 24 are phenyl;
m is 0 or 1; and
X is a coordinated halo or trifluoroacetate ligand.
2. The palladium(II) complex of claim 1 , wherein R 18 and R 19 are the same and are cyclohexyl.
3. The palladium(II) complex of claim 1 , wherein the complex of formula (2) is:
4. A process for preparing a complex of formula (2):
wherein:
R 12 is an optionally substituted straight-chain C 1-20 alkyl, optionally substituted branched-chain C 3-20 alkyl, optionally substituted C 3-20 cycloalkyl, optionally substituted C 6-20 aryl, or optionally substituted heteroaryl having 1-20 carbon atoms;
R 18 and R 19 are, independently, -Me, -Et, - n Pr, — i Pr, - n Bu, - i Bu, cyclohexyl, or cycloheptyl;
R 20 and R 21 are both hydrogen;
R 22 , R 23 , and R 24 are phenyl;
m is 0 or 1; and
X is a coordinated halo or trifluoroacetate ligand;
the process comprising reacting a complex of formula (3) with a monodentate bi-heteroaryl tertiary phosphine ligand of formula (5) to form the complex of formula (2):
5. A process for performing a carbon-carbon coupling reaction in the presence of a catalyst, the process comprising using the complex of formula (2) of claim 1 .
6. A process for performing a carbon-heteroatom coupling reaction in the presence of a catalyst, the process comprising using the complex of formula (2) of claim 1 .
7. The palladium(II) complex of claim 1 , wherein each R 12 is independently an optionally substituted straight-chain C 1-20 alkyl, optionally substituted branched-chain C 3-20 alkyl, or an optionally substituted C 6-20 aryl.
8. The palladium(II) complex of claim 1 , wherein each R 12 is independently an optionally substituted straight-chain C 1-20 alkyl or an optionally substituted C 6-20 aryl.
9. The palladium(II) complex of claim 1 , wherein each R 12 is independently a methyl, phenyl, or substituted phenyl group.
10. The palladium(II) complex of claim 1 , wherein X is a halo group.
11. The palladium(II) complex of claim 1 , wherein X is chloro.
12. The palladium complex of claim 1 , wherein
R 18 and R 19 are both cyclohexyl;
R 12 is methyl, phenyl, or substituted phenyl group;
R 20 and R 21 are hydrogen;
R 22 , R 23 , and R 24 are phenyl;
m is 0 or 1; and
X is chloro.