Rhodium(I)/Binap complexes catalyze highly enantioselective additions of methyl- and arylaluminum reagents to cyclic α,β-unsaturated N-tosyl ketimines. Depending on the solvent and substituents at the ring, the reaction occurs either in a 1,2-manner to deliver α-tertiary allylic amines or in a 1,4-manner to yield, after subsequent reduction, 3-substituted cycloalkyl amines. Well known in the case of the respective cycloalkenones, these first transformations of the aza-analogues enable the synthesis of amine structures of pharmaceutical and biochemical interest.

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N‐Sulfonylimines of cycloalk‐2‐enones are well‐suited for the enantioselective rhodium(I)/binap‐catalyzed 1,4‐additions of arylzinc halides. The cyclic enamides, obtained after quenching, are sensitive towards chromatography, but can undergo diastereoselective reductions to furnish cis‐ or trans‐3‐arylcycloalkylamines with five‐ to seven‐membered rings. The 1,4‐addition is not influenced by a methyl group at C‐5 of six‐membered rings, providing further configurational options. 3‐Arylcycloalkylamines are subunits in a number of bioactive substances and can also be oxidatively transformed into cyclic γ‐amino acids.magnified image

Background: Large intrathoracic airway defects may be closed using a pedicled latissimus dorsi (LD) flap, with rewarding results. This study addresses the question of whether this holds true for extrathoracic non-circumferential tracheal defects. Methods: A cervical segment of the trachea of 4 × 1 cm was resected in 9 white male pigs. The defect was stented with a silicone stent for 3 months and closed either by an LD flap alone (group a, n = 3), an LD flap with an attached rib segment covered by pleura (group b, n = 3), or an LD flap reinforced by a perforated polylactide (MacroPore^®) plate (group c, n = 3). The trachea was assessed by rigid endoscopy at 3 and 4 months and histologically at 4 months postoperatively. Results: The degree of stenosis at the level of the reconstruction at 4 months was 25, 50 and 75% in group a, 15, 50 and 60% in group b, and 20, 95 and 95% in group c, respectively. The percentage of the defect covered by columnar epithelium was 100% in all animals of group a, 60, 100 and 100% in group b, and 10, 0 and 0% in group c. Resorption of the rib was seen in all animals of group b and obstructive inflammatory polyps were found in 2 animals of group c. Conclusion: Pedicled LD flaps provided less satisfactory results for closure of large non-circumferential extrathoracic airway defects than observed after intrathoracic reconstruction. A pedicled rib segment added to the LD flap did not improve the results obtained from LD flap repair alone, and an embedded MacroPore^® prosthesis may result in severe airway stenosis due to plate migration and intense inflammatory reaction protruding into the tracheal lumen.

The first synthesis of N-tosyl imines from various cyclopent-2-enones and cyclohex-2-enones was achieved by direct condensation with tosyl amide in the presence of TiCl(OEt) 3 and Et 3 N. In addition, N-tert-butylsulfonyl imines from five-to seven-membered cycloalk-2-enones were obtained through formation of the respective oximes and subsequent Hudson reaction. These compounds are easy to handle solids and they are interesting starting materials for a variety of transformations.