114095-60-2Relevant academic research and scientific papers
Metal-free domino Cloke-Wilson rearrangement-hydration-dimerization of cyclopropane carbaldehydes: A facile access to oxybis(2-aryltetrahydrofuran) derivatives
Banerjee, Prabal,Dey, Raghunath,Rajput, Shruti
, (2020/03/13)
In this work, we have demonstrated a metal-free transformation of cyclopropane carbaldehydes to oxybis(2-aryltetrahydrofuran) derivatives via a domino Cloke-Wilson rearrangement-hydration-dimerization sequence. Commercially inexpensive p-toluene sulfonic acid (PTSA) was used as a Br?nsted acid catalyst, and reactions were conducted in an open-flask. Detection of reaction intermediates were carried to get an insight into the reaction pathway.
Picosecond radical kinetics. Rate constants for ring openings of 2-aryl-substituted cyclopropylcarbinyl radicals
Newcomb,Choi,Toy
, p. 1123 - 1135 (2007/10/03)
The kinetics of ring openings of a series of eight (trans-2-arylcyclopropyl)methyl radicals (1) were studied by indirect kinetic methods using Barton's PTOC esters as radical precursors and reaction with PhSeH as the competition reaction. The substituents were CF3, F, Me, and OMe located on both the para and meta positions of the aromatic ring. Syntheses of the radical precursors and the products of the radical reactions are described. Kinetics were determined between -43 and 25°C in four cases (CF3 and OMe substituents) and at 0 and 25°C in the other four cases. The rate constants at 25°C ranged from 1.0 x 1011 s-1 (p-CH3) to 4.1 x 1011 s-1 (p-CF3). The relatively large acceleration of the p-CF3 group, ca. 2.5 times as fast as the parent system with Ar = Ph, correlates well with Adam's ΔD substituent parameters but not with other radical substituent parameters. These calibrated radical rearrangements provide a new set of ultrafast reactions that can be applied in mechanistic probe studies.
ARYLCYCLOPROPANE PHOTOCHEMISTRY. UNUSUAL AROMATIC SUBSTITUENT EFFECTS ON THE PHOTOCHEMICAL REARRANGEMENT OF (2-ARYLCYCLOPROPYL)METHYL ACETATES TO 1-ARYLHOMOALLYL ACETATES.
Hixson,Franke,Gere,Xing
, p. 3601 - 3610 (2007/10/02)
Irradiation of trans(2-arylcyclopropyl)methyl acetates a 4-butenyl-1-arylacetate (7a,b,d-h) via an ionic mechanism from the singlet state. Similar rearrangements occurred with exo-(1,1a,6,6a-tetrahydrocycloprop left bracket a right bracket inden-1-yl)methyl acetate and the 4-cyano derivative. Excited state reaction rate constants were determined from reactant fluorescence lifetimes and product quantum yields. It is concluded that the rate-determining step involves conversion of the initially formed aromatic excited state to a reactive cyclopropane excited state and that cyclopropane to aromatic ring charge transfer enhances this process.
