Advanced Organic Chemistry/ Organic Synthesis – CH 621

C-C Bond Formation through Carbanions

Bela TorokDepartment of Chemistry

University of Massachusetts BostonBoston, MA

C-C bond formation through carbanions

Stability of carbanions

- Carbanions stibilized by two –M groups

- Carbanions stabilized by one –M group

- Carbanions stabilized by P or S

- Nucleophilic acylations

- Alkene, arene, heteroarene nucleophiles

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

Knoevenagel condensation

C-C bond formation through carbanions

Knoevenagel condensation

C-C bond formation through carbanions

Doebner condensation

C-C bond formation through carbanions

C-C bond formation through carbanions

Moderate acidity: pKa

9-10 nitromethane

19-27 others Equilibrium concentration of the carbanion

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

Claisen estercondensation

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

Indirect method tounsaturated aldehydes

C-C bond formation through carbanions

C-C bond formation through carbanions

Georg WittigNobel Prize1979

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

C-C bond formation through carbanions

Wilsmeier-Haack-Arnoldreaction

C-C bond formation through carbanions

Wilsmeier-Haack-reaction

C-C bond formation through carbanions

Reimer-Tiemannreaction

Kolbe-Schmittreaction

C-C bond formation through carbanions

C-C bond formation through carbanions

Mannichreaction

C-C bond formation through carbanions

Mannichreaction

Summary

Summary

Summary

Summary