Macrocyclic ligands and their complexes for bifunctional molecular catalysis
Disclosed herein are embodiments of chiral and achiral macrocyclic polydentate ligands and methods of preparing the same. Disclosed herein are also embodiments of metal coordination complexes derived from these macrocyclic polydentate ligands and methods of preparing the same. The metal coordination complexes described herein, can be used for a variety of catalytic reactions, including hydrogenation and transfer hydrogenation of unsaturated organic compounds, dehydrogenation of alcohols and boranes, an asymmetric Michael-type addition reaction, or an aerobic oxidative kinetic resolution of an organic compound, dehydrogenative couplings and other catalytic transformations.
1. A macrocyclic ligand of Formula 1A, 1B, 1C or 1D:
wherein:
Q is phosphorus;
each L is independently selected from a lone pair (or its absence), oxygen, BH 3 , a hydrogen, a substituted or unsubstituted C 1-6 alkyl, a substituted or unsubstituted C 3-6 cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted arylalkyl;
each Y is independently selected from a functionality containing a heteroatom selected from NH, O, S, PR, or an optionally substituted CH 2 group or its absence, wherein R is selected from hydrogen, a substituted or unsubstituted C 1-6 alkyl, a substituted or unsubstituted C 3-6 cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted arylalkyl;
a, b, c, and d can independently be an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; and
R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independently at each occurrence H, a substituted or unsubstituted C 1-6 alkyl, a substituted or unsubstituted C 3-6 cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylalkyl, or a combination thereof.
2. The macrocyclic ligand of claim 1 , wherein each of the R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 can independently be alkyl, alkenyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heteroaryl, alkyl-aryl/alkeny-aryl/alkynyl-aryl, alkyl-heteroaryl/alkenyl-heteroaryl/alkynyl-heteroaryl, heteroalkyl-aryl/heteroalkenyl-aryl/heteroalkynyl-aryl, heteroalkyl-heteroaryl/heteroalkenyl-heteroaryl/heteroalkynyl-heteroaryl or any combination thereof.
3. The macrocyclic ligand of claim 1 , wherein the ligand is selected from:
4. The macrocyclic ligand of claim 1 , wherein the ligand is selected from:
5. The macrocyclic ligand of claim 1 , wherein the ligand is:
6. The macrocyclic ligand of claim 1 , wherein each L is a substituted or unsubstituted C 1-6 alkyl.
7. The macrocyclic ligand of claim 1 , wherein at least one L is a substituted or unsubstituted C 1-6 alkyl.
8. The macrocyclic ligand of claim 1 , wherein at least one L is a substituted or unsubstituted C 3-6 cycloalkyl.
9. The macrocyclic ligand of claim 1 , wherein at least one L is a substituted or unsubstituted aryl.
10. The macrocyclic ligand of claim 1 , wherein each Y is —CH 2 —.
11. The macrocyclic ligand of claim 1 , wherein a, b, c, and are each independently 0 or 1.
12. The macrocyclic ligand of claim 1 , wherein the macrocyclic ligand is of Formula 1A.
13. The macrocyclic ligand of claim 1 , wherein each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 is a hydrogen.
14. The macrocyclic ligand of claim 1 , wherein each L is a methyl.
15. The macrocyclic ligand of claim 1 , wherein each L is a phenyl.
16. The macrocyclic ligand of claim 10 , wherein a, b, c, and are each independently 0 or 1, and each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 is a hydrogen.