74936-98-4Relevant articles and documents
Enantioselective bromolactonization using an S-alkyl thiocarbamate catalyst
Jiang, Xiaojian,Tan, Chong Kiat,Zhou, Ling,Yeung, Ying-Yeung
supporting information; experimental part, p. 7771 - 7775 (2012/09/07)
The apple never falls far from the tree: S-alkyl thiocarbamate 1 (see scheme, NBP=N-bromophthalimide) was prepared in high yield through a synthetic sequence involving a Newman-Kwart rearrangement of the corresponding O-alkyl thiocarbamates. Compound 1 was used to catalyze bromolactonization, thus providing enantioenriched δ-lactones in excellent yield and enantioselectivity. Copyright
Catalytic Asymmetric Induction. Highly Enantioselective Addition of Dialkylzincs to Aldehydes Using Chiral Pyrrolidinylmethanols and Their Metal Salts
Soai, Kenso,Ookawa, Atsuhiro,Kaba, Tatsuya,Ogawa, Kazuo
, p. 7111 - 7115 (2007/10/02)
A series of chiral pyrrolidinylmethanols were synthesized from (S)-proline.Optically active secondary alcohols (R and S enantiomers, respectively) in up to 100percent enantiomeric excess (ee) were obtained in high yields from the enantioselective addition of dialkylzincs to aldehydes catalyzed by 2-5 mol percent of chiral pyrrolidinylmethanols.The sense of the asymmetric induction and the degrees of enantioselectivities were highly dependent on the structure of the catalysts. (+)-DPMPM (3, tertiary amino tertiary alcohol) catalyzed the reaction of aryl, α,β-unsaturated, and aliphatic aldehydes to afford (S) alcohols in high ee's.When the lithium salt of 3 was employed as catalyst in the reactions of aryl and α,β-unsaturated aldehydes, the ee's of (S) alcohols reached 100percent.On the other hand, (-)-erythro-PNPM (10, tertiary amino secondary alcohol) afforded (R) alcohols in high ee (100percent ee).The steric course of the reaction is discussed.
