Phosphite‐Catalyzed C−H Allylation of Azaarenes via an Enantioselective [2,3]‐Aza‐Wittig Rearrangement
作者:Abdul Motaleb、Soniya Rani、Tamal Das、Rajesh G. Gonnade、Pradip Maity
DOI:10.1002/anie.201906681
日期:2019.10
A phosphite-mediated [2,3]-aza-Wittig rearrangement has been developed for the regio- and enantioselective allylic alkylation of six-membered heteroaromatic compounds (azaarenes). The nucleophilic phosphite adducts of N-allyl salts undergo a stereoselective base-mediated aza-Wittig rearrangement and dissociation of the chiral phosphite for overall C-H functionalization of azaarenes. This method provides
Chiral-Anion-Dependent Inversion of Diastereo- and Enantioselectivity in Carbonyl Crotylation via Ruthenium-Catalyzed Butadiene Hydrohydroxyalkylation
作者:Emma L. McInturff、Eiji Yamaguchi、Michael J. Krische
DOI:10.1021/ja311208a
日期:2012.12.26
The ruthenium catalyst generated in situ from H(2)Ru(CO)(PPh(3))(3), (S)-SEGPHOS, and a TADDOL-derived phosphoric acid promotes butadienehydrohydroxyalkylation to form enantiomerically enriched products. Notably, the observed diastereo- and enantioselectivity is the opposite of that observed using BINOL-derived phosphate counterions in combination with (S)-SEGPHOS, the same enantiomer of the chiral
Synthesis, characterization and co-ordination chemistry of dioxolanedipyrazoles
作者:Thomas Jozak、Yu Sun、Werner R. Thiel
DOI:10.1039/c1nj20148d
日期:——
pyrazoles. These ligands can be considered as nitrogen donor analogues to the well established chiral bidentate DIOP ligands which had found wide applications in enantioselective catalysis. The co-ordinationchemistry of these ligands is shown exemplarily for palladium(II) and rhodium(I) complexes. All compounds were completely characterized by means of NMR and IR spectroscopy and by elemental analysis.