The induced proximity of reaction centers of two substrates in the confined cavity of cages reduces dramatically the entropy costs of reactions between substrates. This leads to unusual reactions between otherwise unreactive molecules. In solution, various organic hosts have provided confined cavities suitable for reactions. [1][2][3][4][5][6][7] However, the simultaneous recognition of two unreactive molecules followed by chemical reactions in the cavity has rarely been achieved. We have previously reported the strong binding of two or more substrates through hydrophobic forces in the cavity of selfassembled cage 1 in aqueous solution, 8 whereby two different substrates can be pairwise selectively recognized and their thermal and photochemical reactions are efficiently promoted under high regio-and stereocontrol. For example, syn-stereoselective [2+2] photoaddition of acenaphthylenes and 1,4-regioselective [2+4] (Diels-Alder) addition of anthracenes with maleimide derivatives have been reported. 7 We hereby report that highly stable arenes 2-6 can undergo [2+2] photo or [2+4] thermal additions cleanly inside the cavity of 1, despite their inertness under ordinary conditions.

Remote chirality at the periphery of a self-assembled cage brings about the slight twist of aromatic rings, which is yet sufficient to induce considerable asymmetric induction (up to 50% ee) in the hitherto unknown [2 + 2] cross photoadditions of fluoranthenes.

No abstract