In a number of synthetic processes, acidic hydrogen from weak organic acids namely alpha hydrogen adjacent carbonyl group quite often removed by base to generate, carbanions
or nitride ion which can then be reacted further as a nucleophile to synthesize many industrially important intermediates & products.
This issue covers reactions of aldehydes and ketones and their derivatives; reactions of carboxylic, phosphoric and sulfonic acids and their derivatives; oxidation and reduction; carbenes and nitrenes; nucleophilic and electrophilic aromatic substitution; carbocations; nucleophilic aliphatic substitution; carbanions
and electrophilic aliphatic substitution; elimination reaction; addition reactions (polar addition and cycloaddition); and molecular rearrangements.
In particular, and because of our ongoing studies on carbanionic species [12-14], we are interested in the stability of the carbanions
derived from adamantane (Fig.
This system performs temperature-sensitive reactions including carbohydrate chemistry, the formation of carbanions
, and other highly reactive intermediates.
In conjunction with butadiene monomer, such an organolithium based system produces allylic carbanions
that are unique in terms of their structure, reactivity and solvency.
Khidre, "Overview of the chemical reactivity of phosphonyl carbanions
toward some carbonnitrogen systems," Current Organic Chemistry, vol.
Chapters summarize findings in the areas of reactions of aldehydes and ketones and their derivatives; reactions of carboxylic, phosphoric, and sulfonic acids and their derivatives; radical reactions; oxidation and reduction; carbenes and nitrenes; nucleophilic aromatic substitution; electrophilic aromatic substitution; carbocations; nucleophilic aliphatic substitution; carbanions
and electrophilic aliphatic substitutions; elimination reactions; polar addition reactions; cycloaddition reactions; and molecular rearrangements.
For example, studies of the superbases and carbanions
are often very sensitive to oxidation.
This includes enantioselective synthesis of [Alpha]-hetereoatom stabilized carbanions
, additions of chirally-modified organometallics to carbonyl compounds, and enantioselective synthesis of natural products, particularly insect pheromones.
In the case of the sequential anionic living polymerization of (meth)acrylic monomers, it is generally known that the nucleophilic attack of polystyryl carbanions
on the caronyl group of (meth)acrylic monomer is the most usual side reaction, leading to the limited monomer conversion and branch formation.
Olefin synthesis with organic phosphonate carbanions