Catalytic enantioselective amination of silyl enol ethers using chiral dirhodium(II) carboxylates: asymmetric formal synthesis of (-)-metazocine.
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 ketones or alpha,beta-enones with [N-(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN=IPh), providing N-(2-nitrophenylsulfonyl)-alpha-amino ketones in high yields and with enantioselectivities of up to 95% ee. The effectiveness of the present catalytic protocol has been demonstrated by an asymmetric formal synthesis of (-)-metazocine.
Anada
Masahiro
M
Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Tanaka
Masahiko
M
Washio
Takuya
T
Yamawaki
Minoru
M
Abe
Takumi
T
Hashimoto
Shunichi
S
D000586:Amination; D002384:Catalysis; D004987:Ethers / Q000737:chemistry*; D015394:Molecular Structure; D009019:Morphinans / Q000138:chemical synthesis*; D009942:Organometallic Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*
D004987:Ethers; D009019:Morphinans; D009942:Organometallic Compounds; D012238:Rhodium; C047238:metazocine