We hypothesized that 1H-perfluoroalkanes (1HPFAs) would form as the presumed carbanion
leaving group of the PFPiA molecules.
The key components of an MA system are electron deficient C=C double bonds (e.g., an acryloyl, the acceptor), acidic C-H bonds (as present in aceto-acetate and malonate moieties, the donor), and a base catalyst strong enough to abstract the proton of this C-H bond yielding a nucleophilic carbanion
that can add to the double bond.
Hakomori, "A rapid permethylation of glycolipid, and polysaccharide catalyzed by methylsulfinyl carbanion
in dimethyl sulfoxide," Journal of Biochemistry, vol.
In the case of the Michael addition, the carbanion
would react with Michael acceptors or [alpha],[beta]-unsaturated compounds to yield polyfunctionalised nitroderivatives .
The reason was that due to the great difference in temperature between the exterior and inside of oil shale sample, the condensation and aromatorization reactions, as well as decomposition of some minerals with carbanion
The radical IV is further reduced to form a benzylic carbanion
V ([c.sub.2], Figure 2(b)).
A plausible mechanistic pathway proposed for the title compounds involves the generation of a carbanion
at the active methylene group ([C.sub.4]-C[H.sub.2]) which is stabilized by coumarin ring .
Taking Scheme la as an example, the Michael addition starts with the deprotonation of BTA (nucleophile) by base or solvent such as NMP with a relatively high proton affinity (923.4 kJ [mot.sup.-1] (15)) used in this work (B:) to result in carbanion
stabilized by its electron-withdrawing groups ([BTA.sup.[??]]).
Methylation was performed with potassium methyl-suphinyl carbanion
and methyl iodide in dimethyl sulphoxide as described by Harris et al.
Highlights included the opening plenary lecture by Gregory Petsko, Brandeis University, entitled, "The Road to Resolution: A Structural Enzymologist's Adventures Beyond 1 Angstrom," and the plenary lecture by NSERC Gold Medalist Tito Scaiano, FCIC, University of Ottawa, entitled, "Carbanion
Studies: From Drug Photostability to Carbanion
Kinetics and New Photocages," on the final day of the conference.
In propagation, intramolecular rearrangements due to hydride([H:.sup.-]) ion or carbanion