Alkylation, base mediated carbanion

Examples of reactions that involve carbanion-mediated alkylations have thus far all involved the formation of an enolate that led to reaction at C2. Alkylation of 17-methyltestosterone, however, favors reaction at C4. Treatment of that enone, 14-1, with methyl iodide in the presence of the strong base potassium tcrt-butoxide leads to the formation of the... 

One advantage of a CRP, such as ATRP, is the ability to control the MW and MWD of copolymers containing functional monomers. Control over MW requires efficient initiation and preservation of activity in the majority of the polymeric chains. However, termination and other side reaaions are also present in ATRP, and they become more prominent as higher MW polymers are targeted. For example, in the copper-mediated ATRP of styrene, a slow termination process was observed, mainly arising from the interaction of the Cu species with both the growing radical and the maaomolecular alkyl halide. The catalytic species can participate in the OSET reactions by either oxidation of polystyryl radicals to carbocations or reduction of radicals to carbanions via reactions with Cu(II) and Cu(l) species. Studies with model compounds and maao-molecular PS species demonstrated that the elimination reaction was accelerated in the presence of the Cu(II) complex. This process was faster for bromine-mediated ATRP than for chlorine-based systems and was more noticeable in polar... 

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