Titanium complexes containing a bridging indenylethylamido ligand have been synthesized and used as catalysts for hydroamination and hydroaminoalkylation reactions. All dichloro titanium complexes (η 5 :η 1 -Ind-C 2 H 4 -NR)TiCl 2 (R = i-Pr (2a), t-Bu (2b), Cy (2c), Ph (2d)), which were prepared by reacting TiCl 4 (Et 2 O) 2 with Li 2 [Ind-C 2 H 4 -NR], were fully characterized by single-crystal X-ray analysis. Reaction of 2a−c with methyllithium gave the thermally sensitive corresponding dimethyl titanium complexes [η 5 :η 1 -Ind-C 2 H 4 -N(alkyl)]TiMe 2 (alkyl = i-Pr (3a), t-Bu (3b), Cy (3c)), while the N-aryl-substituted dimethyl titanium complexes [η 5 :η 1 -Ind-C 2 H 4 -N(aryl)]-TiMe 2 (aryl = Ph (3d), p-MeOC 6 H 4 (3e)) were directly prepared by reacting Li 2 [Ind-C 2 H 4 -N(aryl)] with in situ generated Cl 2 TiMe 2 . In the case of complex 3d, the molecular structure could be determined by single-crystal X-ray analysis. All dimethyl titanium complexes (η 5 :η 1 -Ind-C 2 H 4 -NR)TiMe 2 (R = i-Pr (3a), t-Bu (3b), Cy (3c), Ph (3d), p-MeOC 6 H 4 (3e)) were finally used as precatalysts for the intermolecular hydroaminoalkylation of 1-octene (4), the intramolecular hydroamination and hydroaminoalkylation reactions of aminoalkenes, and the intermolecular hydroamination of 1-phenylpropyne (12). These experiments showed that the N substituent of the indenylethylamido ligand strongly influences the activity of the catalysts in the individual reactions.

No abstract

Dedicated to Professor Jürgen Martens in honor of his outstanding contribution to synthetic organic chemistry DOI: http://dx.doi.org/10.3998/ark.5550190.p008.859 AbstractVarious indenylethylamines are synthesized for the first time by reductive amination of 2-(1H-inden-1-yl)acetaldehyde with commercially available primary amines. In addition, a new twostep synthesis of 2-(1H-inden-1-yl)acetaldehyde that uses inexpensive indene and 2-bromo-1,1-diethoxyethane as starting materials is presented. Finally, a selected indenylethylamine is used as a ligand precursor for the synthesis of a corresponding indenylethylamido titanium complex. The latter result paves the way for applications of corresponding complexes as catalysts for important chemical reactions.

Self‐assembled monolayers (SAMs) of oligoethylene glycol (OEG)‐terminated alkanethiolates on gold, which are used to control protein adsorption and cell adhesion, were patterned by reaction with Br2/HOBr electrogenerated at a microelectrode of a scanning electrochemical microscope (SECM). The spreading of the Br2 diffusion layers was limited by a homogeneous reaction with cystamine or L‐cystine as scavengers. The influence of process parameters on the patterning process was explored by simulation and combinatorial experiments. The experimental determination of pattern sizes from SECM feedback images was verified by scanning force microscopy. The simulation considered the local Br2 formation as well as Br2 consumption in the reaction with the OEG SAM, by reduction at the gold substrate, and by the homogeneous scavenging reaction. It used experimentally determined diffusion coefficients and rate constants of the scavenging reaction. and Experiments and simulation confirmed the existence of regions in the parameter space, in which the patterning process is robust against small variation of the parameters working distance, pulse time and scavenger excess.

Abstract.A simple, reliable, and reproducible procedure for the multigram synthesis of highly pure bis(indenyl)dimethyltitanium is presented. The procedure relies on a one-pot conversion of inexpensive indene, methyllithium, and titanium tetrachloride to [Ind 2 TiMe 2 ] and