Sustainable approaches for asymmetric synthesis – from domino reactions to Chiral Carbon Dots as nano-organocatalysts

Organocatalysis is considered the third pilar of asymmetric synthesis and, due to the green aspects of organocatalytic procedures, has paved the way to the extensions of organic stereoselective synthesis horizons towards efficient, practical and more sustainable methodologies. For instance, organocatalyzed cascade reactions and sequential catalysis have been shown to be excellent candidates because of the number of steps that can occur under the same reaction conditions, thereby leading directly to high molecular complexity, in a cost-effective protocol.[1] Additionally, the technological advancement contributed to the application of other techniques such as electroorganic chemistry and photocatalysis to organocatalytic protocols, especially in the transferring of organocatalysis to heterogeneous processes. Within this context, carbon dots (CDs) are an emerging class of carbon-based nanoparticles, characterized by low-toxicity, biocompatibility, excellent suspensibility, and remarkable photoluminescent properties. CDs have therefore found many applications, including heterogeneous catalysis and photocatalysis.[2] In this presentation, some sustainable approaches for asymmetric synthesis will be described: i) the sequential stereoselective synthesis of spiro-decalin oxindoles; ii) electroorganic synthesis of Chiral Carbon Dots and their application as nano-organocatalysts for an asymmetric aldol reaction.