The easily accessible 2‐(methylamino)pyridinato titanium complex initially synthesized by Kempe is used as catalyst for efficient intramolecular hydroaminoalkylation reactions of secondary aminoalkenes. The corresponding reactions of N‐aryl‐substituted 1‐aminohept‐6‐enes and 1‐aminohex‐5‐enes directly give access to 2‐methylcyclohexyl‐ or 2‐methylcyclopentylamines in good yields. In addition, intramolecular hydroaminoalkylations of an N‐alkyl‐substituted secondary aminoalkene and a geminally β‐disubstituted substrate are described for the first time. While all products are formed as mixtures of two diastereoisomers, better trans/cis ratios are observed during the formation of 2‐methylcylopentylamines.magnified image

Self-assembly reactions with low valent early transition metals, leading to neutral multinuclear complexes are rare. Mostly late transition metals like Pt, Pd or Ru together with Nheterocycles or O-donor-based ligands are used to form supramolecular coordination complexes. This paper reports on selfassembly reactions of low valent titanocene and zirconocene units and five-membered N-heterocycles as bridging ligands. These reactions lead to novel molecular triangles and rectangles with the metal centers marking the vertices. Five different imidazole derivatives and four different metallocene precursors were used. For the first time, molecular triangles and architec-Scheme 1. Molecular quadrangle with pyrazine I and 4,4′-bipyridine II and a combination of both III as bridging ligands.[a]

The N-heterocyclic olefin (NHO) ImMe4=CH2 (2) (ImMe4=CH2 = (MeCNMe)2C=CH2) was employed for the synthesis of the titanium complex 3 derived from an NHO ligand precursor. By reacting 2 with the...