Diels-Alder in Aqueous Molecular Hosts: Unusual Regioselectivity and Efficient Catalysis
Michito Yoshizawa, Masazumi Tamura, Makoto Fujita*
Science 2006, 312, 251-254.
Rebek J. et al. Nature 1997, 385, 50-52.
Diels-Alder Reaction
Epoxidation
Angew. Chem. Int. Ed. Engl. 2001, 40, 4239-4242.
Angew. Chem. Int. Ed. Engl. 2004, 43, 6748-6751.
aza-Cope rearrangement
Fe
Regioselective cycloaddition
Org. Lett. 2002, 4, 327-329.
1
4
9
10
3a 79.43b 49.8
Barrier (kJ mol-1)
ΔE = 29.6Chem. Phys. Lett. 2003, 368, 630-638.
Diels-Alder Reaction
anthracenes phthalimides
B-ring A-ring
J. Am. Chem. Soc. 1965, 87, 4649-4651 .
1’
H2O
70 oC
Nature 1995, 378, 469-471.
J. Am. Chem. Soc. 2004, 126, 6846-6847.
Angew. Chem. Int. Ed. Engl. 2001, 40, 1879-1884.
RSi(OMe)3
Cyclic siloxane formation
J. Am. Chem. Soc. 2001, 123, 10454-10459
Td
C3v
5 hr
Syn-1,4-Diels-Alder adduct (5)
Yield : > 98 %
No other : 1,9-adduct or anti-1,4-adduct
9 ,10-Diels-Alder adduct
44 %
without 1
π-π stacking interaction(3.3 Å)
N
O
O
4b3c
OH
+
19, 10 -adduct
5 hr
> 99 %
(10 mmol%)
aromatic-aromatic orcharge-transfer interactions
the host-guest aromatic stacking interaction
the encapsulated product is considerablydestabilized and smoothly replaced by incoming reagents