Optimisation, scope and mechanism of the platinum‐catalysed addition of indoles to indolylallenes is reported here to give 2,3′‐BIMs with a novel core structure very relevant for pharmaceutical industry. The reaction is modulated by the electronic properties of the substituents on both indoles, with the 2,3′‐BIMs favoured when electron donating groups are present. Although simple at first, a complex mechanism has been uncovered that explains the different behaviour of these systems with platinum when compared with other metals (e.g. gold). Detailed labelling studies have shown Pt‐catalysed 6‐endo‐trig cyclisation of the indollylallene as the first step of the reaction and the involvement of two cyclic vinyl‐platinum intermediates in equilibrium through a platinum carbene, as the key intermediates of the catalytic cycle towards the second nucleophilic attack and formation of the BIMs.

l-Tyrosine provides a precursor for a practical synthesis of the unstable primary metabolite l-arogenate and some stabilised arogenate analogues.

Organometallic synthesis is a powerful tool to make novel molecules with frameworks not encountered in natural products. In this context the platinum‐catalysed reaction of indolylallenes with indole nucleophiles was discovered which gives substituted tetrahydropyrido[1,2a]indoles, an original type of 2,3′‐BIM with a framework not observed thus far in nature and of interest to the pharmaceutical industry. The reaction is unique to platinum catalysis and the study of the mechanism uncovered a complex reaction pathway that may help in the understanding of the divergent reactivity of platinum compared to other metals. More information can be found in the Full Paper by M. P. Muñoz, et al. on page 6105.