Synthesis of chiral hydroxyproline based organocatalysts and their applications in Aldol and Michael addition reactions / Noraishah Abdullah

Chiral compounds are common in nature and can have profoundly varied effects in chiral biological systems based on stereochemistry. Organic chemist creates chiral molecules utilizing enantiopure substance, reagent, and catalyst to produce a single enantiomer with ideal pharmacology, toxicity, pharmacokinetics, and metabolism properties. This leads to asymmetric reactions using more efficient organocatalysts to prevent waste, increase atom economy, save energy, and increase stereoselectivity. One interesting organocatalyst that is demanded is prolineamide-derived organocatalyst. The first aim of this study is to synthesize prolineamide-derived organocatalyst via 3-hydroxyproline precursor. A new synthetic strategy was developed starting with the Michael addition reaction of glycine ethyl ester, 79 with ethyl acrylate, 78, to give the desired ethyl-3-[(2-ethoxy-2-oxoethyl)amino]propanoate, 80 with an overall yield of 62%. The next strategy was to protect the nitrogen atom with tert-butoxycarbonyl (BOC) using a simple method utilizing NaOH as the base, resulting in 81% yield