116172-13-5Relevant academic research and scientific papers
Catalytic enantioselective amination of silyl enol ethers using chiral dirhodium(II) carboxylates: Asymmetric formal synthesis of (-)-metazocine
Anada, Masahiro,Tanaka, Masahiko,Washio, Takuya,Yamawaki, Minoru,Abe, Takumi,Hashimoto, Shunichi
, p. 4559 - 4562 (2008/03/13)
(Chemical Equation Presented) Dirhodium(II) tetrakis[N- tetrafluorophthaloyl-(S)-tert-leucinate], Rh2(S-TFPTTL)4, is an exceptionally efficient catalyst for enantioselective aminations of silyl enol ethers derived from acyclic ketone
General asymmetric synthesis of isoquinoline alkaloids. Enantioselective hydrogenation of enamides catalyzed by BINAP-ruthenium(II) complexes
Kitamura,Hsiao,Ohta,Tsukamoto,Ohta,Takaya,Noyori
, p. 297 - 310 (2007/10/02)
In the presence of a small amount of RuX2[(R)- or (S)-BINAP] (X = anionic ligand) a wide range of (Z)-2-acyl-1-benzylidene-1,2,3,4- tetrahydroisoquinolines are hydrogenated to give the saturated products in nearly quantitative yields and in high (up to 100%) optical yields. The enamide substrates are selectively prepared by N-acylation of the corresponding 1-benzylated 3,4-dihydroisoquinolines under suitable acylation conditions; some crystalline materials having low solubility are obtained by a second-order Z/E stereomutation technique utilizing the double-bond photolability and lattice energy effects. This asymmetric hydrogenation sets the key stereogenic center in a predictable manner, either R or S flexibly, at the C(1) position of the benzylated tetrahydroisoquinolines. The chiral products are converted by standard functional group modification to tetrahydropapaverine, laudanosine, tretoquinol, norreticuline, etc. Hydrogenation of the simple 1-methylene substrate is used for synthesis of salsolidine. This enantioselective hydrogenation is applied to the synthesis of morphine and its artificial analogues such as morphinans and benzomorphans of either chirality. A mnemonic device is presented for predicting the reactivity and enantiofacial selection of the BINAP-Ru catalyzed hydrogenation. Reaction with BINAP-Rh catalyst proceeds with a lower enantioselectivity and an opposite sense of asymmetric induction.
