for the synthesis of various sulfur-tethered vinylogous carbonates in good to excellent yields. Important features of the developed reaction include wide functional group tolerance, excellent chemo- and regioselectivity, and efficient rearrangement involving the carbonyl motif. The present reaction also equally works well with α-selenoesters for the synthesis of seleno-containing vinylogous carbonates
Visible light mediated reductions of ethers, amines and sulfides
作者:Timothy M. Monos、Gabriel Magallanes、Leanne J. Sebren、Corey R.J. Stephenson
DOI:10.1016/j.jphotochem.2016.05.014
日期:2016.9
Visible light-mediated photoredox catalysis enables the chemoselective reduction of activated carbon–heteroatom bonds as a function of reduction potential. The expansion of the scope of C–X bond reductions towards less activated motifs, such as ethers, amines and sulfides, is important to both organic synthesis and macromolecular degradation method development. In the present report, exploration of
We report the first example of highly enantioselective synthesis of structurally diverse chiral dithioketalsviaasymmetric sulfenylation of various types of S-based nucleophiles, catalyzed by a cheap cinchona alkaloid derivative, dihydroquinine.
Herein, a series of indenone structures containing the SCF3 group and an adjacent chiral quaternary stereocenter were synthesized by an asymmetric Michael addition reaction using an ion pair catalyst derivedfrom amino acids. The desired products were obtained in excellent yields (up to 98%) and good to high stereoselectivities (up to 97% ee and >20:1 dr).
Several examples of racemization process at a quaternary carbon center affecting Michael adducts were reported. A brief statement to prevent the occurrence of the interfering retro-Michael reaction was also presented.