Diels-Alder in Aqueous Molecular Hosts: Unusual Regioselectivity and Efficient Catalysis

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