A comprehensive investigation and optimisation on the proteinogenic amino acid catalysed homo aldol condensation

A one-pot biocatalytic and organocatalytic cascade delivers high titers of 2-ethyl-2-hexenal from n-butanol

“…22,57 When twenty proteinogenic amino acids were screened as homo aldol condensation catalysts in ethanol a number of promising candidates, including lysine, emerged. 58 Thus, we first screened all 20 amino acids under conditions relevant to Fig. 3 Effect of biocatalyst and initial alcohol loadings on overall system efficiency.…”

“…22,57 When twenty proteinogenic amino acids were screened as homo aldol condensation catalysts in ethanol a number of promising candidates, including lysine, emerged. 58 Thus, we first screened all 20 amino acids under conditions relevant to our system (50 mM phosphate buffer, pH 7.4, RT, 24 h with 200 mM n -butyraldehyde) (ESI† Fig. S1).…”

Recycling of two molecular catalysts in the hydroformylation/aldol condensation tandem reaction using one multiphase system

“…In a work by Ostrowski et al all 20 proteinogenic amino acids were compared for their catalytic activity in aldol condensations of aldehydes in ethanol. 36 L-Tryptophan and L-phenylalanine performed best and tryptophan was successfully applied in a water system, too. Similarly, in our biphasic system both amino acids performed excellently with hexanal conversions of 95% and 94%, respectively.…”

Divergent Total Syntheses of Hetero-Oligomeric Iridoid Glycosides

“…It is known that amino acids can facilitate the aldol reaction. 13 Therefore, the aldol reaction with amino acids using 9 as a model substrate was investigated (Table 1).…”

“…To demonstrate our biosynthetic hypothesis, the aldol reaction was performed with 1 equiv of L-tryptophan in DMF (Table 1, entry 1). The desired aldol reaction proceeded smoothly; (E)-aldosecologanin octaacetate (13) was isolated as a single isomer in excellent yield after 28 h (86%). (E)-Aldosecologanin ( 14) is a dimeric iridoid glycoside isolated from Lonicera japonica.…”