New SCS Pd pincer complexes featuring a noninnocent indenediide backbone show high catalytic activity in cycloisomerization. A variety of alkylidene lactams (five-to seven-membered rings) have been prepared efficiently from N-tosyl alkynylamides, and good results have also been obtained with challenging alkynoic acids.

The hydroformylation of 10-undecenitrile (1), a route towards polyamide-12, has been studied using Ru-diphosphite catalysts. The reactions proceeded effectively by in situ combination of chloro precursors such as RuCl 2 (PPh 3) 3 and RuCl 2 (DMSO) 4 with Biphephos. High productivities (TON up to 15,000 mol(aldehyde).mol(Ru) −1) were achieved by carrying the reactions at low catalyst loading ([1] 0 /[Ru] = 20,000), at 120 °C in toluene or acetonitrile under 20 bars CO/H 2 (1:1), with 20 equiv of Biphephos vs. Ru. Up to 75% chemoselectivity for the aldehydes and very high regioselectivities for the linear aldehyde (l/b = 99:1) were reached under such optimized conditions. Lower loadings of Biphephos (down to 2.5 equiv. vs. Ru) did not affect the chemo-and regioselectivities but the activity. The Ru-Biphephos combinations showed a non-optimized hydroformylation TOF HF of ca. 2-7 min −1 , that is ca. 1-2 order of magnitude lower than that of analogous Rh-based systems (TOF HF = ca. 80 min −1). These Ru-Biphephos systems are, however, incapable, under the conditions suitable for selective hydroformylation, to promote isomerization of internal olefins, and hence to achieve a tandem isomerization-hydroformylation process.