). (This latter possibility had been highlighted in the experimental report of this reaction system by Feng and co-workers. ) What this shows is that the newly proposed sandwich conformation of the aromatic additive is the more correctpreferred conformation of the system, both prior to and during the transition state formation, as the reaction proceeds. We have also below). This further highlights the role of the aromatic additive as a second catalyst, and shows how it increases the enantioselectivity of the desired product during the reaction. There have been a vast number of organocatalytic reactions where the addition of aromatic additives such as acids or alcohols, has been seen to have a beneficial effect on the yield and the enantioselectivity. The conventional explanation for this has been their ability to increase the pKa, or in some cases, create a proton shuttle mechanism, or act as a hydrogen bonding agent with one of the substrates. However, till date, there has been no systematic investigation of the role that the additive may be playing. It is easy to see that such a study is essential, because without understanding the exact role of the additive vis-à-vis asymmetric organocatalysis, it is not possible to systematically improve the catalysts systems, other than by trial and error. The current computational study with density functional theory (DFT) is the first systematic study of the role of additives, focusing on aromatic additives, and investigating their role in a wide variety of experimentally reported systems. What the investigations demonstrate is that aromatic additives can form a stable sandwich complex, stabilizing both the electrophile and the nucleophile through non-covalent interactions, while maintaining the correct relative orientation of the two substrates relative to each other. This has been demonstrated for a wide range of organocatalyst systems employing different aromatic additives. We note here that, while the majority of the cases studied showed this favourable interaction, there were two cases out of nine where such sandwich complex formation was seen to be unfavourable. For such systems, the beneficial role of the additive would be due to other factors, such as increasing the pKa, acting as a proton shuttle or hydrogen bonding with one of the substrates. This result also points at a simple manner in which the role of the aromatic additive in new asymmetric organocatalysis could be evaluated: a few optimization calculations involving the proposed aromatic additive and the organocatalyst system would quickly reveal whether the role uncovered in the current work would be operational in the system that would be experimentally investigated.