Pd-catalyzed addition of arylboronic acids to N-tosylarylimines was described by employing easily prepared, air-stable aminophosphine ligands, cheap inorganic base, and common organic solvents, providing diarylmethylamine derivatives through one-pot synthesis in moderate to good yields. The efficiency of this reaction was demonstrated by the compatibility with nitro, trifluoromethyl, fluoro, chloro, and methoxy groups. Moreover, rigorous exclusion of air/moisture is not required in these transformations.
A rhodium complex coordinated with a chiral diene, (R,R)-2,5-diphenylbicyclo[2.2.2]octa-2,5-diene (Ph-bod), catalyzed the asymmetric addition of dimethylzinc to N-tosylarylimines to give high yields of chiral 1-aryl-1-ethylamines with high enantioselectivity (94-98% ee).
A three-componentcouplingreaction of arynes, isocyanides and N-tosylaldimines has been developed to offer modest to high yields of diverse 2-iminoisoindolines in one step. Intermediacy of arynes in the coupling has been verified by the reaction of unsymmetrical arynes.
Enantioselective Addition of Silicon Nucleophiles to Aldimines Using a Preformed NHC-Copper(I) Complex as the Catalyst
作者:Alexander Hensel、Kazuhiko Nagura、Lukas B. Delvos、Martin Oestreich
DOI:10.1002/anie.201402086
日期:2014.5.5
asymmetric addition of siliconnucleophiles to typical prochiral acceptors, the enantioselective 1,2‐addition to aldimines, is addressed. Activation of the SiB bond in the silicon pronucleophile by a copper(I) alkoxide with McQuade’s chiral six‐membered N‐heterocyclic carbene as a supporting ligand releases the siliconnucleophile, which adds to various aldimines with high levels of enantioselectivity. The
A novel synthetic route to optically active 1,3-oxazolidines via formal [3 + 2] cycloaddition in the presence of cinchona-alkaloid-thiourea-based bifunctional organocatalysts is reported. This protocol gives easy access to a wide range of chiral 1,3-oxazolidines. In addition, the results show that bifunctional organocatalysts can effect the intramolecular aza-Michael addition, leading to the asymmetric synthesis of nitrogen-containing heterocycles.