Development of new P-chiral phosphorodiamidite ligands having a pyrrolo[1,2-c]diazaphosphol-1-one unit and their application to regio- and enantioselective iridium-catalyzed allylic etherification.
Ten types of new P-chiral phosphorodiamidite ligands having pyrrolo[1,2-c][1,3,2]diazaphosphol-1-one backbone were designed and prepared. They were preliminarily utilized for iridium-catalyzed asymmetric allylic etherification of cinnamyl carbonate with phenol, where both R- and S-products were obtained with good enantioselectivity (up to 74% ee) by changing the N- and P-substituents of the ligands. The opposite enantioselectivity in iridium-catalyzed allylic substitution was explained by DFT calculations of the energy difference of the pi-allyliridium-phosphorodiamidite intermediates.
Kimura
Masahiro
M
Institute for Molecular Science (IMS), CREST, and The Graduate University for Advanced Studies, Higashiyama 5-1, Myodaiji, Okazaki 444-8787, Japan.
Uozumi
Yasuhiro
Y