Synthesis of hindered chiral guanidine bases starting from (S)-(N,N-dialkyl-aminomethyl)pyrrolidines and BrCN
摘要:
An efficient method for the preparation of hindered chiral quanidines using cyanogen bromide is described. The reaction between BrCN and vicinal diamines derived from (S)-2-(N,N-dialkyl-amiilomethyl)-pyrrolidines provides chiral substituted cyanamides. The cyanamide derivatives reacted with secondary amines in hexafluoroisopropanol at reflux to form chiral hindered guanidines, which were isolated in good to excellent yields (70-96%). The chiral guanidines were prepared in an effort to design sophisticated chiral guanidine catalysts for asymmetric synthesis. (c) 2006 Elsevier Ltd. All rights reserved.
This invention aims at providing a catalyst for producing an optically active aldehyde or an optically active ketone, which is an optically active carbonyl compound, by carrying out selective asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, particularly a catalyst which is insoluble in a reaction mixture for obtaining optically active citronellal which is useful as a flavor or fragrance, by carrying out selective asymmetric hydrogenation of citral, geranial or neral; and a method for producing a corresponding optically active carbonyl compound. The invention relates to a catalyst for asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, which comprises a powder of at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table, or a metal-supported substance in which at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table is supported on a support, an optically active cyclic nitrogen-containing compound and an acid.
Asymmetric Trasformation of Symmetrical Epoxides to Allylic Alcohols by Lithium (<i>S</i>)-2-(<i>N</i>,<i>N</i>-Disubstituted aminomethyl)pyrrolidide
作者:Masatoshi Asami
DOI:10.1246/bcsj.63.721
日期:1990.3
Enantioselective deprotonation of symmetrical epoxides was studied by using chiral lithium amide, prepared from (S)-2-(N,N-disubstituted aminomethyl)pyrrolidine and butyllithium. Chiral allylic alcohols were obtained with moderate to high enantiomeric excesses (ee’s) (41–92% ee) from several cyclic and acyclic epoxides employing lithium (S)-2-(1-pyrrolidinylmethyl)pyrrolidide in tetrahydrofuran (THF) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).
Highly Regio- and Enantioselective Organocatalytic Conjugate Addition of Alkyl Methyl Ketones to a β-Silylmethylene Malonate
作者:Raghunath Chowdhury、Sunil K. Ghosh
DOI:10.1021/ol900803n
日期:2009.8.6
(S)-N-(2-Pyrrolidinylmethyl)pyrrolidine/trifluoroacetic acid (3:1) combination catalyzed the direct addition of alkyl methyl ketones to β-dimethyl(phenyl)silylmethylene malonate at the methyl terminal with high yield and excellent regio- and enantioselectivity. The silyl group played crucial roles in regioselection and substrate reactivity.
Diastereoselective Synthesis of Tetrasubstituted Propargylamines via Hydroamination and Metalation of 1-Alkynes and Their Enantioselective Conversion to Trisubstituted Chiral Allenes
1-alkynes to give the corresponding propargylamine derivatives in up to 94% yield and 99% regioselectivity. The diastereomerically pure chiralpropargylamines were obtained in 23–89% yield using optically active 2-benzyl morpholine and N-methyl camphanyl piperazine. These chiralpropargylamines are readily converted to the corresponding trisubstitued chiralallenes in 71–89% yields with up to 99% ee
[EN] NOVEL BETULINIC SUBSTITUTED AMIDE DERIVATIVES AS HIV INHIBITORS<br/>[FR] NOUVEAUX DÉRIVÉS D'AMIDE SUBSTITUÉS BÉTULINIQUES UTILISÉS COMME INHIBITEURS DU VIH
申请人:HETERO RESEARCH FOUNDATION
公开号:WO2017017630A1
公开(公告)日:2017-02-02
The present invention relates to novel betulinic substituted amide compounds of formula (I); and pharmaceutically acceptable salts thereof, wherein R1, R2, R3, R4, R5, R6, R7, R8, X, Y, Z1, Z2, Z3 and are Formula (II) as defined herein. The invention novel betulinic substituted amide derivatives, related compounds, and pharmaceutical compositions useful for the therapeutic treatment of viral diseases and particularly HIV mediated diseases.