Most Combinatorial LPOS Reaction: Reductive Amination with a Scavenger

Abstract

Reactions of liquid-phase parallel synthesis are subject to quite stringent requirements by quite different criteria. Collections of starting reagents should be cheap and diverse while the reaction conditions should be simple and mild, and the products should be obtained in high yields and without complicated purification. For biological tests, the final molecule should contain a predetermined “pharmacophore” fragment. Many reactions fail to meet such criteria. For example, certain C–C bond formation reactions can be considered unsuitable. (Diels–Alder reactions and even condensations produce a lot of admixtures; cross-coupling makes use of hardly accessible reagents, etc.) Much more suitable are reactions involving nucleophilic nitrogen atom (formation of amides, sulfamides, hydrazides, or hydrazones), the best of which is the formation of compounds with an aminoalkyl group. Substituted aminoalkyl group (NHRCH₂– or NR₂CH₂–) is a well-known pharmacophore group in a great variety of medicines and natural compounds.