77298-35-2Relevant academic research and scientific papers
Copper-catalyzed fragmentation-rearrangement sequence of cycloketoxime esters
Wu, Yixiao,Zhao, Binlin,Shi, Zhuangzhi,Yuan, Yu
, (2019/12/24)
Copper-catalyzed fragmentation-rearrangement sequence of cycloketoxime esters is reported. This strategy provides direct access to diverse ring-opening acyloxylation nitriles avoiding the use of toxic cyanic reagents with good atom economy and well functi
Visible-Light Photocatalysis Employing Dye-Sensitized Semiconductor: Selective Aerobic Oxidation of Benzyl Ethers
Ren, Li,Yang, Ming-Meng,Tung, Chen-Ho,Wu, Li-Zhu,Cong, Huan
, p. 8134 - 8138 (2017/12/08)
The aerobic oxidation is an attractive approach toward environmentally benign synthesis of fine chemicals. In addition, dye-sensitized semiconductors are underdeveloped photocatalysts for selective organic synthesis. With the aid of catalytic eosin Y-sensitized titanium dioxide, we have developed efficient aerobic photooxidation of benzyl ethers to benzoates, featuring low cost, high atom economy, broad substrate scope, and user-friendly setup. Furthermore, preliminary mechanistic studies established that the reaction pathway likely entails a photoinduced, radical-based two-step process via an isolable peroxide intermediate.
Synthesis of δ- And ε-cyanoesters by zinc-catalyzed ring-opening of cyclic ethers with acid chlorides and subsequent cyanation
Enthaler, Stephan,Weidauer, Maik
, p. 168 - 175 (2012/03/27)
In the present study, the zinc-catalyzed cleavage of cyclic ethers with acid halides as nucleophiles to yield chloroesters with different chain length has been investigated in detail. In the presence of straightforward and commercially available zinc salts as pre-catalysts excellent yields and selectivities were feasible. After studying the reaction conditions and the scope of the method, several efforts were carried out to understand the reaction mechanism. The obtained chloroesters were subsequently converted to δ- and ε-cyano esters, which are useful precursors in natural product synthesis. Graphical Abstract: [Figure not available: see fulltext.]
β-Functionalised radicals in organic synthesis: 2-Acyloxyalkyl radicals from 2-acyloxyalkyl iodides by the tin route
Foubelo, Francisco,Lloret, Francisco,Yus, Miguel
, p. 5131 - 5138 (2007/10/02)
The reaction of iodoesters 1a-c with electrophilic olefins 2a-d and in situ generated tributyltin hydride (from a substoichiometric amount of tributyltin chloride and an excess of sodium borohydride) in the presence of a catalytic amound of AIBN in ethanol at 0 to 20°C yields the expected coupling products 3aa-3cd. Products 4 resulting from an iodine/hydrogen exchange are also obtained as by-products in variable amounts. The stereochemistry of the coupling reaction is studied: starting from trans-2-iodocyclohexyl acetate (1d) and methyl acrylate (2a) a 1/3 mixture of the corresponding cis/trans diastereoisomers is obtained. This result indicates that the corresponding radical coupling is not stereospecific.
Elimination and Addition Reactions. Part 43. Eliminative Fission of Cyclobutanes and the Relationship between Strain and Reactivity in Cyclobutanes and Cyclopropanes
Earl, Harold A.,Stirling, Charles J. M.
, p. 1273 - 1280 (2007/10/02)
Eliminative fission of cyclobutanes has been compared with that of analogous cyclopropanes; reactivity differences of 103.7-104.8 have been determined.In both sets of compounds, mechanisms have been shown to involve rate-determining ring fission.The possibilities that the large reactivity differences between the comparably strained systems are due either to peculiarity in the cyclobutane structures or to their abnormally slow deprotonation are rejected.Analysis of strain in the two systems suggests that as ring fission occurs, dispersal of the excess of enthalpy of the cyclobutanes is a less sensitive function of extension of a bond in the ring than for the cyclopropanes.The behaviour of these systems is compared with cleavage of cyclopropanes and cyclobutanes in other reactions; the results are remarkably similar.Calculations using the MINDO3 programme have been carried out for eliminative fissions of cyclopropylmethyl and cyclobutylmethyl carbanions.These reproduce remarkably closely the difference between the heats of formation of the species at the energy maxima for fission of each ring size; the maximum for fission of the cyclobutane is considerably displaced along the reaction co-ordinate towards product.
