Pyrrole-based Organocatalysts for Chemical Rearrangements and Living Polymerizations Catharine H. Larsen, Department of Chemistry, University of California, Riverside Dipyrromethanes constitute half a porphyrin, or an iron-free heme, leading to a wide range of applications. The high interest in the fundamental properties and intrinsic reactivity of achiral dipyrrin and dipyrromethane complexes of iron, zinc, copper, boron, nickel, and more is due to their establishment as: ¥ water-stable environmental sensors ¥ light-harvesting architectures ¥ materials for metal-organic frameworks ¥ imaging agents in living cells ¥ atom-transfer catalysts ¥ redox-active ligands
R
NH
R
H
R
NH HN
N
dipyrrin
R
NH HN
dipyrromethanes
Ph Mes
Me
Me
Me
Me
N
N
N
N
CH2NR2 N N
N Fe
t-Bu O
Cl
N Cu N
N
N
t-Bu
B
Me
Mes
N
F
F
N
Me
Mes
Ni
Mes N
N
Mes
Fe N
Ph
We developed the first synthesis of dipyrromethanes with chiral centers installed adjacent to both nitrogens with 99% enantioselectivity to expand dipyrrin systems and as backbones for new ligands. Ph asymmetric dipyrrin complexes
H
Ph
future
Me
H O
2 steps O HO
OH
Me
O
NH HN work
Me
Me
N H
asymmetric redox-active ligands
NH HN 2 steps Ph HO
OH
