Naphthalene Diels-Alder in a self-assembled molecular flask.
Despite its inertness toward pericyclic reactions under common conditions, naphthalenes readily undergo Diels-Alder reactions when coencapsulated with a suitable dienophile within the cavity of a self-assembled host. Localization of the reactant pair significantly reduces the entropic cost of the reaction, and preorganization within the host cavity controls both the regio- and stereoselectivity of the reaction: electronically disfavored exo adducts were obtained, and with substituted naphthalenes, the reaction takes place on the less electron-rich, unsubstituted ring. Our findings highlight the fact that judicious tuning of substrate size and shape within molecular flasks can unveil new and unusual reactivities for otherwise unreactive molecules.
Murase
Takashi
T
Department of Applied Chemistry, School of Engineering, The University of Tokyo, and CREST, Japan Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Horiuchi
Shinnosuke
S
Fujita
Makoto
M
D018360:Crystallography, X-Ray; D003500:Cyclization; D008958:Models, Molecular; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D011789:Quantum Theory; D013237:Stereoisomerism
D009281:Naphthalenes; C031721:naphthalene