Palladium-Catalyzed Regioselective Synthesis of 1-Benzoazepine Carbonitriles from<i>o</i>-Alkynylanilines via 7-<i>endo</i>-dig Annulation and Cyanation
作者:Ganesh Kumar Dhandabani、Mohana Reddy Mutra、Jeh-Jeng Wang
DOI:10.1002/adsc.201800865
日期:2018.12.21
report a three‐component, one‐pot cascade reaction involving an imination/annulation/cyanation sequence for the synthesis of 1‐benzoazepine carbonitrile derivatives using readily available o‐alkynylanilines, cyclic ketones and trimethylsilyl cyanide. This regio‐ and stereoselective reaction was achieved by combining palladium(II) trifluoroacetate and copper(II) acetate in dimethyl sulfoxide. The important
Groth, U.; Richter, L.; Schoellkopf, U., Liebigs Annalen der Chemie, 1992, # 3, p. 199 - 202
作者:Groth, U.、Richter, L.、Schoellkopf, U.
DOI:——
日期:——
Developing P-Stereogenic, Planar–Chiral P-Alkene Ligands: Monodentate, Bidentate, and Double Agostic Coordination Modes on Ru(II)
作者:Alberto Herrera、Alexander Grasruck、Frank W. Heinemann、Andreas Scheurer、Ahmed Chelouan、Sibylle Frieß、Falk Seidel、Romano Dorta
DOI:10.1021/acs.organomet.6b00879
日期:2017.2.13
10-Phenyl-5H-dibenz[b,f]azepine (5) is synthesized by Suzuki cross coupling of the protected bromo alkene 4 with PhB(OH)(2). 5 reacts with PCl3 to afford the dichlorophosphanyl-azepine 6 in >90% yield. Alkylation of 6 with 1 equiv of t-BuMgBr leads, after recrystallization in Et2O, to the diastereomerically enriched (dr > 98:2) chloride rac-7, which the crystal structure reveals to be the (pS,R-P)/(pR,S-P) pair. The fact that rac-7 crystallizes in the Sohncke space group P2(1)2(1)2(1) opens up the possibility of a mechanical separation of the enantiomers. Methylation of rac-7 is perfectly stereoselective with inversion of configuration at the P atom to yield the new ligand rac-8 as the (R,R)/(S,S) pair. The corresponding BH3-protected diastereomer rac-9 (i.e., the (R,S)/(S,R) pair), is isolated after flash column chromatography in 73% yield. Compounds 59 are accessible in multigram quantities. X-ray crystal structures of Ru(II) complexes demonstrate the ambidentate nature of ligand rac-8: Complex 10 is exclusively P-coordinated, while in complex 11 two ligands bind Ru through their P donors and stabilize the 14-electron metal center with a double agostic interaction. In complex 12, the ligand coordinates in a kappa P,eta(2)-alkene bidentate fashion.