title: Synthesis of aryl group-modified DIOP dioxides (Ar-DIOPOs) and their application as modular Lewis base catalysts.
abstract: Treatment of an optically pure tartaric acid-derived diiodide and various secondary phosphine oxides with LHMDS provides the corresponding aryl group-modified DIOP dioxides (Ar-DIOPOs). The activities of Ar-DIOPOs as Lewis base catalysts were investigated for several asymmetric transformations using chlorosilane reagents. The p-tolyl-substituted DIOPO (p-tolyl-DIOPO) was most effective for the reductive aldol reaction of chalcone and aldehydes with trichlorosilane, whereas the 2,8-dimethylphenoxaphosphine-derived DIOPO (DMPP-DIOPO) afforded the best enantioselectivity for the phosphonylation of conjugated aldehydes and the chlorinative aldol reaction of an ynone and benzaldehyde.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohmaru
authors.forename: Norimasa
authors.initials: N
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Mizutani
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kotani
authors.forename: Masaharu
authors.initials: M
authors.lastname: Sugiura
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakajima
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D002073:Butanes / Q000737:chemistry*; D002384:Catalysis; D058115:Lewis Bases / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C527007:2,3- O-isopropylidene-2,3-dihydroxyl-1,4-bis(diphenylphosphino)butane; D000447:Aldehydes; D002073:Butanes; D058115:Lewis Bases; D010087:Oxides; D010720:Phosphines