Regio- and Stereospecific Formation of Protected Allylic Alcohols via Zirconium-Mediated S<sub>N</sub>2‘ Substitution of Allylic Chlorides
作者:Richard J. Fox、Gojko Lalic、Robert G. Bergman
DOI:10.1021/ja075967i
日期:2007.11.1
regio- and stereospecific SN2‘ substitution reaction between a zirconium oxo complex and allylicchloride has been achieved. The resulting allylic alcohol or TBS-protected allylic ether products were isolated in good to excellent yields with a wide range of E-allylic chlorides. A mechanism for the SN2‘ allylic substitution consistent with kinetic, stereochemical, and secondary isotope effect studies
Organocatalyzed Tsuji–Trost reaction: a new method for the closure of five- and six-membered rings
作者:Bojan Vulovic、Filip Bihelovic、Radomir Matovic、Radomir N. Saicic
DOI:10.1016/j.tet.2009.10.006
日期:2009.12
A combination of organotransition metal catalysis and organocatalysis allows for Tsuji–Trost 5-exo- and 6-exo-cyclizations of aldehydes. This transformation can also be accomplished as a catalytic asymmetric reaction, which affords vinylcyclopentane derivatives with up to 98%ee.
Organocatalyzed Cyclizations of π-Allylpalladium Complexes: A New Method for the Construction of Five- and Six-Membered Rings
作者:Filip Bihelovic、Radomir Matovic、Bojan Vulovic、Radomir N. Saicic
DOI:10.1021/ol7023554
日期:2007.11.1
Synergic combination of organotransition metal catalysis and organocatalysis allows, for the first time, the Tsuji-Trost cyclization of aldehydes. A catalytic asymmetric variant of the reaction is also possible.
A cascade intramolecular azide‐alkene 1,3‐dipolar cycloaddition/1,2 enamine and/or 1,4 enamine additionreaction sequence has been developed, and provides access to a variety of nitrogen containing heterocycles from readily available ω‐azido alkenes.
Formation of Bicyclic Ethers from Lewis Acid Promoted Cyclizations of Cyclic Oxonium Ions
作者:Pradip K. Sasmal、Martin E. Maier
DOI:10.1021/ol025570d
日期:2002.4.1
Oxacycles carrying a vinyl group and an acetal were extended with a cyclization terminator (vinyl silane or vinyl sulfide) by Suzuki coupling. Treatment with Lewis acid induced cyclization to provide bicyclic ethers in reasonable yields. In the case of the vinyl silane, an ene-like mechanism is preferred, whereas the thioenol ether enters into a Prins-type reaction channel. In one instance, the bicyclic