A Positional Scanning Approach to the Discovery of Dipeptide-Based Catalysts for the Enantioselective Addition of Vinylzinc Reagents to Aldehydes
作者:Christopher M. Sprout、Meaghan L. Richmond、Christopher T. Seto
DOI:10.1021/jo051342w
日期:2005.9.1
crude form as catalysts for the asymmetric addition of vinylzinc reagents to aldehydes to give chiralallylicalcohols. Three sites of diversity on the ligands were optimized using a positional scanning approach. The optimized structure from the library, ligand 54, was found to catalyze the formation of 10 different (E)-allylicalcohols with enantioselectivities ranging from 90% to 95% ee. This ligand was
Accessing Both Retention and Inversion Pathways in Stereospecific, Nickel-Catalyzed Miyaura Borylations of Allylic Pivalates
作者:Qi Zhou、Harathi D. Srinivas、Songnan Zhang、Mary P. Watson
DOI:10.1021/jacs.6b07396
日期:2016.9.14
enable access to eitherenantiomer of allylboronate product from a single enantiomer of readily prepared allylic pivalate substrate. Excellent functional group tolerance, yields, regioselectivities, and stereochemical fidelities are observed. The stereochemical switch from stereoretention to stereoinversion largely depends upon solvent and can be explained by competitive pathways for the oxidative
Solid-Phase Synthesis of Chiral <i>N</i>-Acylethylenediamines and Their Use as Ligands for the Asymmetric Addition of Alkylzinc and Alkenylzinc Reagents to Aldehydes
作者:Christopher M. Sprout、Meaghan L. Richmond、Christopher T. Seto
DOI:10.1021/jo049160+
日期:2004.10.1
synthesis of chiral N-acylethylenediamine ligands. The ligands are obtained in good yield and purity, without the need for chromatography or other purification methods. Several new and previously reported ligands were prepared using this procedure. These compounds were examined as catalysts for the enantioselectiveaddition of alkylzincreagents to aldehydes. In all cases, the crude ligands from the solid-phase
Enantioselective Addition of Vinylzinc Reagents to Aldehydes Catalyzed by Modular Ligands Derived from Amino Acids
作者:Meaghan L. Richmond、Christopher M. Sprout、Christopher T. Seto
DOI:10.1021/jo051313l
日期:2005.10.1
enantioselectivities that ranged from 52 to 91% ee and yields that ranged from 40 to 90%. This ligand was especially effective for the reaction of aromatic aldehydes with vinylzinc reagentsderivedfrom bulky terminal alkynes. Ligand 3d catalyzed the addition of (E)-(3,3-dimethylbut-1-enyl)(ethyl)zinc to 2-naphthaldehyde to give (R,E)-4,4-dimethyl-1-(naphthalene-1-yl)pent-2-en-1-ol in 89% ee. The ee of this
[EN] PROCESSES FOR HIGHLY ENANTIO-AND DIASTEREOSELECTIVE SYNTHESIS OF ACYCLIC EPOXY ALCOHOLS AND ALLYLIC EPOXY ALCOHOLS<br/>[FR] PROCEDES DE SYNTHESE HAUTEMENT ENANTIOSELECTIVE ET DIASTEREOSELECTIVE D'EPOXYALCOOLS ACYCLIQUES ET D'EPOXYALCOOLS ALLYLIQUES
申请人:UNIV PENNSYLVANIA
公开号:WO2005087755A1
公开(公告)日:2005-09-22
The inventive subject matter relates to novel processes for making an epoxy alcohol from an aldehyde, comprising the steps of: (a) adding (i) an organozinc compound or (ii) divinylzinc compound and an diorganozinc compound to said aldehyde in the presence of a first catalyst to form an allylic alkoxide compound; and (b) epoxidizing said allylic alkoxide compound in the presence of an oxidant and a second catalyst.