Palladium-Catalyzed Intramolecular C−O Bond Formation
摘要:
A number of oxygen heterocycles were synthesized using the palladium-catalyzed intramolecular etherification of aryl halides by employing di-tert-butylphosphinobiaryl ligands. The reaction proceeds under mild conditions using weak bases such as Cs2CO3 or K3PO4. A variety of functional groups are tolerated in the reaction. and enantioenriched alcohols can be coupled without erosion of optical purity. The mildness of the reaction conditions allows for the use of polyfunctionalized substrates. This method was used as the key step in the synthesis of MKC-242, an antidepressant currently in clinical trials. The synthesis of MKC-242 was achieved in 40% overall yield from commercially available sesamol and acrylonitrile,
Asymmetric Catalytic Synthesis of α-Aryloxy Alcohols: Kinetic Resolution of Terminal Epoxides via Highly Enantioselective Ring-Opening with Phenols
作者:Joseph M. Ready、Eric N. Jacobsen
DOI:10.1021/ja9910917
日期:1999.6.1
terminal epoxides with catalyst 3b4 (Scheme 1, Nu ) OH) suggested that (salen)Co(III) complexes might also serve as effective catalysts for the enantioselective addition of phenols to epoxides. This strategy has proven successful, and we report here the first examples of kinetic resolution of epoxides with phenols, with the isolation of 1-aryloxy 2-alcohols (1) in high ee’s and yields. Reaction of 2.2
A High-Yield, General Method for the Catalytic Formation of Oxygen Heterocycles
作者:Karen E. Torraca、Shin-Itsu Kuwabe、Stephen L. Buchwald
DOI:10.1021/ja005698v
日期:2000.12.1
STEREOSELECTIVE RING OPENING REACTIONS
申请人:PRESIDENT AND FELLOWS OF HARVARD COLLEGE
公开号:EP1104395A1
公开(公告)日:2001-06-06
[EN] STEREOSELECTIVE RING OPENING REACTIONS<br/>[FR] REACTIONS STEREOSELECTIVES D'OUVERTURE DE CYCLE
申请人:HARVARD COLLEGE
公开号:WO2000009463A1
公开(公告)日:2000-02-24
The present invention relates to a process for stereoselective or regioselective chemical synthesis which generally comprises reacting a nucleophile, selected from the group consisting of water, alcohols, carboxylic acids, and thiols, and a racemic or diastereomeric mixture of a cyclic substrate in the presence of a non-racemic, chiral catalyst to effect a kinetic resolution of the cyclic substrate. The present invention also relates to hydrolytic kinetic resolutions of racemic and diastereomeric mixtures of epoxides.
A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
作者:David E. White、Pamela M. Tadross、Zhe Lu、Eric N. Jacobsen
DOI:10.1016/j.tet.2014.03.043
日期:2014.7
enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen) Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminalepoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of