Mineral catalysis of a potentially prebiotic aldol condensation.
Minerals may have played a significant role in chemical evolution. In the course of investigating the chemistry of phosphonoacetaldehyde (PAL), an analogue of glycolaldehyde phosphate, we have observed a striking case of catalysis by the layered hydroxide mineral hydrotalcite ([Mg2Al(OH)6][Cl.nH2O]). In neutral or moderately basic aqueous solutions, PAL is unreactive even at a concentration of 0.1 M. In the presence of a large excess of NaOH (2 M), the compound undergoes aldol condensation to produce a dimer containing a C3-C4 double-bond. In dilute neutral solutions and in the presence of the mineral, however, condensation takes place rapidly, to produce a dimer which is almost exclusively the C2-C3 unsaturated product.
De Graaf
R M
RM
Evolutionary Biology Research Group, University of Nijmegen, The Netherlands.
Visscher
J
J
Xu
Y
Y
Arrhenius
G
G
Schwartz
A W
AW
D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D000536:Aluminum Hydroxide / Q000737:chemistry*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D019281:Dimerization; D019418:Evolution, Chemical; D008276:Magnesium Hydroxide / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D063065:Organophosphonates / Q000138:chemical synthesis / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D013057:Spectrum Analysis
D000447:Aldehydes; D063065:Organophosphonates; C003126:phosphonoacetaldehyde; C010467:hydrotalcite; D012972:Sodium Hydroxide; D000536:Aluminum Hydroxide; C116609:3-hydroxybutanal; D000079:Acetaldehyde; D008276:Magnesium Hydroxide