Olefins devoid of directing or activating groups have been dicarbofunctionalized here with two electrophilic carbon sources under reductive conditions. Simultaneous formation of one C(sp 3 )−C(sp 3 ) and one C(sp 3 )−C(sp 2 ) bond across a variety of unbiased π-systems proceeds with exquisite selectivity by the combination of a Ni catalyst with TDAE as sacrificial reductant. Control experiments and computational studies revealed the feasibility of a radical-based mechanism involving, formally, two interconnected Ni(I)/Ni(III) processes and demonstrated the different ability of Ni(I) species (Ni(I)I vs PhNi(I)) to reduce the C(sp 3 )−I bond. The role of the reductant was also investigated in depth, suggesting that a oneelectron reduction of Ni(II) species to Ni(I) is thermodynamically favored. Further, the preferential activation of alkyl vs aryl halides by ArNi(I) complexes as well as the high affinity of ArNi(II) for secondary over tertiary C-centered radicals explains the lack of undesired homo-and direct coupling products (Ar−Ar, Ar−Alk) in these transformations.

Gold‐ and palladium‐catalyzed cyclization of easily accessible indole‐tethered allenols allows the efficient synthesis of carbazole derivatives under mild conditions.

We report a full study on the novel regioselective Ni-catalyzed hydroborylative cyclization of enynes using HBpin as the borylation agent.

Allene chemistry in the presence of transition metal complexes is nowadays a very important topic that underpins many challenges and advances in organic synthesis. The amount of research articles covering new transformations of allenes is vast and the development of enantioselective reactions involving allenes has flourished in the last 10-15 years. In this review we cover three important topics in allene chemistry that we feel are timely appropriate for this special issue celebrating the work of Prof Trost: the metal-catalysed reactions involving chirality transfer from chiral allenes to products; the analysis of the possible racemization processes that have been observed in the interaction of some metals with allenes; and the chirality transfer using racemic allenes in reactions catalysed by metal complexes bearing chiral ligands to produce enantioriched products. We have focussed the review on intermolecular addition reactions as they are still much less explored than the intramolecular version.