173239-50-4Relevant articles and documents
Chiral recyclable fluorous disulfonamide ligand for catalytic enantioselective cyclopropanation of allylic alcohols
Kawashima, Yuya,Ezawa, Tetsuya,Yamamura, Mai,Harada, Taisuke,Noguchi, Takuya,Miura, Tsuyoshi,Imai, Nobuyuki
, p. 8585 - 8592 (2016/01/25)
Allylic alcohols reacted with Et2Zn and CH2I2 in the presence of a catalytic amount of fluorous disulfonamide 3a to afford the corresponding cyclopropylmethanols in 69%-quantitative yields with 49-85% ee. Recovery of the fluorous ligand 3a was readily performed from the reaction mixture by the fluorous solid-phase extraction (FSPE), and the recovered 3a could be reused without a significant loss of the catalytic activity and enantioselectivity.
N,N,N′,N′-Tetraalkyl-2,2′-dihydroxy-1,1′- binaphthyl-3,3′-dicarboxamides: Novel Chiral Auxiliaries for Asymmetric Simons-Smith Cyclopropanation of Allylic Alcohols and for Asymmetric Diethylzinc Addition to Aldehydes
Kitajima, Hiroshi,Ito, Katsuji,Aoki, Yuko,Katsuki, Tsutomu
, p. 207 - 217 (2007/10/03)
The newly introduced tittle compounds were found to be efficient chiral auxiliaries for the asymmetric Simmons-Smith cyclopropanation of allylic alcohols and for asymmetric addition of diethylzinc to aldehydes. For example, Simmons- Smith cyclopropanation of cinnamyl alcohol in the presence of N,N,N′,N′-tetraethyl-2,2′-dihydroxy-1, 1′-binaphthyl-3, 3′-dicarboxamide (1b) proceeded with high enantioselectivity of 94% ee and addition of diethylzinc to benzaldehyde in the presence of N,N,N′,N′-tetraisopropyl-2,2′-dihydroxy-1,1′-binaphthyl- 3,3′-dicarboxamide (1e) proceeded with enantioselectivity of 99% ee. Although the reaction mechanism of these reactions is still nuclear, a monomeric seven-membered 2,2′-dihydroxy-1,1′-binaphthyl-3,3′-dicarboxamide (1)-Zn complex is considered to be an active species which catalyzes the above reactions, on the basis of NMR experiments.
Asymmetric Simmons-Smith Cyclopropanation of E-Allylic Alcohols Using 1,1'-Bi-2-naphthol-3,3'-dicarboxamide as a Chiral Auxiliary
Kitajima, Hiroshi,Aoki, Yuko,Ito, Katsuji,Katsuki, Tsutomu
, p. 1113 - 1114 (2007/10/03)
N,N,N',N'-Tetraethyl-1,1'-bi-naphthol-3,3'-dicarboxamide (1b) was found to be an effective chiral auxiliary for asymmetric Simmons-Smith cyclopropanation and high enantioselectivity greater than 85percent ee was achieved in the reaction of E-allylic alcohols.
