Amplification by compartmentalization

Abstract

Autocatalysis and chemical amplification are properties of living systems that can lead to increased responsiveness and to self-replication. Here we describe a synthetic system in which a unique form of reagent compartmentalization gives rise to nonlinear kinetics that are subject to the precise size- and shape-selectivity of the host. The reactivity is reminiscent of autocatalytic behaviour, in which there is no direct contact between reagents and products, and our approach offers a general way to impose complex chemical behaviour onto synthetic systems.

Self‐Assembled Nanoreactors

“…For example, Rebek's group has elegantly demonstrated that encapsulation of reagents can be utilized to effect chemical amplification in a reaction that takes place outside the capsule. 87,114 The reaction of p-toluic acid 48 or p-ethylbenzoic acid 49 with p-ethylaniline 50 and N,N′-dicyclohexylcarbodiimide (DCC) 51 yields anilides 52 and 53 at almost identical rates, together with N,N′-dicyclohexylurea 54 (DCU) and N-acylurea side-products ( Figure 10). In the presence of a stoichiometric amount of capsule 26-26 (see Figure 4), the reaction rates decreased substantially, and, in addition, p-toluic acid appeared to react much faster than p-ethylbenzoic acid.…”

Molecules within molecules: Recognition through self-assembly

“…Addition of benzoic acid 15 and aniline 16 to the solution of DCC encapsulated within capsule 8 sets off a reaction cascade (Fig. 3) (27). Trace DCC that is free in solution promotes the formation of an amide bond between the acid and aniline reactants.…”

Chemical amplification with encapsulated reagents

“…The relative affinity of the capsule for the guests is DCU ϳ 4a Ͼ DCC. The discrimination of subtle structural differences coupled with the compartmentalization of reagents gives rise to nonlinear kinetics and autocatalytic behavior in reactions involving encapsulated DCC (12).…”