Ketonization of Incarcerated Acetophenone Enol

Abstract

A free-standing simple enol has been generated inside a carceplex. Rates of ketonization under various conditions were determined; ketonization is extremely slow as compared to the rate in solution. Complexed water is required, and the mechanism proceeds via formation of an enolate followed by protonation at carbon by the same molecule of water that removed the proton from the enol. Acid or base retards ketonization by removing water from the cavity.

Theoretical study of the geometrical and electronic structures and thermochemistry of spherophanes

“…This approach has allowed spectroscopic studies and characterisation of reaction intermediates [6][7][8]. For example, the rearrangement of singlet phenylnitrene to 1-azacyclohepta-1,2,4,6-tetraene inside hemicarcerand has been achieved by Warmuth et al [6].…”

“…Spherophane1 (Spher1; molecular structure C 48 H 24 ) is the simplest spherical molecule obtained by such a manipulation. Spher1 may be derived by adding 24 hydrogen atoms to the C 48 fullerene studied by Dunlop and Taylor [21] or the designed structure 24 (4,6,8) with 12 squares, eight hexagons and six octagons in the reference [22].…”

Reactions Inside Carcerands

“…90 The photochemistry of arylalkylketones is rich and important to organic synthesis. 91 Photochemical reactions of arylalkylketones typically arise from the triplet 3 ( n , π * ) state.…”

Inner‐Phase Reaction Dynamics: The Influence of Hemicarcerand Polarizability and Shape on the Potential Energy Surface of an Inner‐Phase Reaction

“…It was dissolved in the minimum amount of CHCl 3 and purified by preparative TLC (SiO 2 ; CHCl 3 ) to yield 4442᭪2 as a white powder (44 mg; 41 % yield). 1 72.8, 69.7, 37.4, 34.6, 32.9, 32.8, 28.4, 26.9, 21.3 (2) 13 In situ Preparation of Hemicarceplex 4445᭪1: Hemicarcerand 4445 (45.5 mg, 0.02 mmol) was dried overnight at 120°C under high vacuum (Ͻ0.01 mm) and was dissolved in CDCl 2 CDCl 2 (0.5 mL). The solution was cooled to 0°C before neat 1 (105 μL) was added.…”

“…(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) active intermediates have been generated and stabilized by preventing their dimerization or the reaction with bulkphase reactants that are too large to enter the inner phase. [6][7][8][9][10][11][12][13][14][15][16][17] Encapsulation has also been applied to investigate fundamental aspects of electron and energy transfer processes, [18][19][20][21][22] to change and control the rate and regiochemistry of bimolecular reactions, [23][24][25][26][27][28][29][30][31][32][33] to amplify reactions, [34] and to alter the position of chemical equilibria. [35] Recently, Rebek and co-workers and Fujita and coworkers showed that Diels-Alder reactions and photochemical [2+2] additions are strongly accelerated in the presence of a self-assembled capsule or coordination cage.…”