Anodic cyclization reactions: probing the chemistry of N,O-ketene acetal derived radical cations
作者:Yung-tzung Huang、Kevin D. Moeller
DOI:10.1016/j.tet.2006.04.009
日期:2006.7
The chemical reactivity of radical cations derived from N,O-ketene acetals has been examined and compared with the reactivity of radical cations derived from both ketene dithioacetals and enol ethers. Synthetically, the N,O-ketene acetal radical cations lead to more efficient cyclization reactions than either the ketene dithioacetal or enol ether derived radical cations. Cyclic voltammetry experiments
Construction of dihydropyran-bridged macrocycles by inverse-electron-demand Diels–Alder reaction
作者:Xiaomei Dong、Qingxia Wang、Qian Zhang、Shuai Xu、Zhihong Wang
DOI:10.1016/j.tet.2013.10.101
日期:2013.12
A variety of dihydropyran-bridged macrocyclic structures were constructed by the inverse-electron-demand Diels Alder reaction of 2-oxo-4-aryl-but-3-enoates. Controlling of the tether length and the position of the activating substituent in the substrates would guide the reaction to the formation of four different types of polycyclic frames, namely bicyclic [n.3.1], bicyclic [n.2.2], tricyclic [n.3.1.1], and tricyclic [n.2.2.2] macrocycles. The intermolecular/intramolecular selectivity of the Diels Alder reaction was virtually governed by the tether length. The reactions were carried out rapidly under mild conditions, and offered a practical method for creating bridged polycyclic structures with large rings from acyclic precursors. (C) 2013 Elsevier Ltd. All rights reserved.
Intramolecular Anodic Olefin Coupling Reactions: A New Approach to the Synthesis of Angularly Fused, Tricyclic Enones
作者:Luzviminda V. Tinao-Wooldridge、Kevin D. Moeller、Christine M. Hudson
DOI:10.1021/jo00088a019
日期:1994.5
A number of intramolecular anodic olefin coupling reactions have been examined in order to determine the feasibility of using a sequential electrochemical oxidation-aldol condensation approach for constructing polycyclic enones. Initially, substrates comprised of an aldehyde enol ether tethered to a ketone enol ether were examined. In a model study, it was shown that such a substrate could lead to a successful electrochemical oxidation-aldol condensation sequence. However, the difficulties associated with both the synthesis and the poor stability of the ketone enol ethers greatly reduced the potential utility of this approach. This problem was circumvented by taking advantage of the compatibility of allylsilane groups with the electrolysis reaction. In these examples, ozonolysis of the electrochemical cyclization product afforded the 1,4-dicarbonyl substrate needed for the aldol condensation. The use of the less reactive allylsilane group in the electrochemical reaction still allowed for the construction of quaternary carbons. Finally a pair of angularly fused, tricyclic enones were synthesized. The regiochemistry of the enone in the product could be controlled by the proper choice of the substrate for the electrolysis and manipulation of the resulting cyclized product.
Huang, Yung-Tzung; Moeller, Kevin D., Organic Letters, 2004, vol. 6, # 23, p. 4199 - 4202