Krapcho Decarboxylation

Schematic representation of the Krapcho Decarboxylation.

Mechanism of the Krapcho Decarboxylation

Mechanism of the Krapcho Decarboxylation

Original publication	Tetrahedron Lett.. 1967, 8, 215. Tetrahedron: Asymmetry. 2012, 23, 852.
Reviews	Arkivoc. 2007, 2, 1. Arkivoc. 2007, 2, 45. J. Chem. Res.. 2011, 35, 67. Org. React.. 1976, 24, 187. Org. React.. 2013, 81, 1.

Sample reactions

intermediate structure

KI

DMF

125 °C, , 70% (2 steps)

intermediate structure

intermediate structure

LiCl

DMSO, H2O

170 °C, 70 min, 83%

intermediate structure

intermediate structure

LiCl

DMSO, H2O

140 °C, 15 min, 71% (4 steps)

intermediate structure

intermediate structure

LiI.3H2O

DMF

Reflux, 18 h, 85%

intermediate structure

intermediate structure

LiI

DMF

Reflux, 2 h, 65% (2 steps)

intermediate structure

intermediate structure

LiI, 2,4,6-Collidine

80 °C, 60 min

intermediate structure

intermediate structure

LiCl

DMSO, H2O

140 °C, 17 h, 97% (2 steps)

intermediate structure

intermediate structure

LiCl

DMF

135 °C, 4 h, 88% (2 steps)

intermediate structure

intermediate structure

LiCl, Et3N.HCl

DMA

130 °C, 2.5 h, 84%

intermediate structure

intermediate structure

NaCl

DMF, H2O

Reflux, 35 h, 69%

intermediate structure

intermediate structure

NaCl

DMF, H2O

Reflux, 35 h, 67% (2 steps)

intermediate structure

intermediate structure

NaCl

DMF, H2O

Reflux, 4 h, 56%

intermediate structure

intermediate structure

LiCl

DMSO, H2O

160 °C, 2 h, 85%

intermediate structure

intermediate structure

LiCl

DMF

140 °C, 3 h, 88%

intermediate structure