Enantioselective Synthesis of Boron-Substituted Quaternary Carbon Stereogenic Centers through NHC-Catalyzed Conjugate Additions of (Pinacolato)boron Units to Enones
作者:Suttipol Radomkit、Amir H. Hoveyda
DOI:10.1002/anie.201309982
日期:2014.3.24
base catalyzed enantioselective boryl conjugate additions (BCAs) that generate products containing boron‐substituted quaternarycarbonstereogeniccenters are disclosed. Reactions are performed in the presence of 1.0–5.0 mol % of a readily accessible chiral accessible N‐heterocyclic carbene (NHC) and commercially available bis(pinacolato)diboron; cyclic or linear α,β‐unsaturated ketones can be used and
Enantioselective Synthesis of Quaternary Carbon Stereogenic Centers through Copper-Catalyzed Conjugate Additions of Aryl- and Alkylaluminum Reagents to Acyclic Trisubstituted Enones
作者:Jennifer A. Dabrowski、Matthew T. Villaume、Amir H. Hoveyda
DOI:10.1002/anie.201304035
日期:2013.7.29
Acyclicquaternarycarbons by conjugateaddition: The first examples of catalytic enantioselectiveconjugateadditions of aryl and alkyl units that generate acyclic all‐carbonquaternarystereogeniccenters have been developed (see scheme). The requisite organoaluminum reagents can either be prepared in situ from easily available organolithiums or purchased at low cost.
Double Asymmetric Hydrogenation of Linear β,β-Disubstituted α,β-Unsaturated Ketones into γ-Substituted Secondary Alcohols using a Dual Catalytic System
β‐unsaturated ketones catalyzed by the DM‐SEGPHOS/DMAPEN/RuII complex with t‐C4H9OK afforded the γ‐substituted secondaryalcohols in high diastereo‐ and enantioselectivities. Some mechanistic experiments suggested that two different reactive species, type (I) and (II), were reversibly formed in this catalytic system: Type (I) with the diamine ligand DMAPEN enantioselectively hydrogenated the enones
Corrigendum: A Multicomponent Ni-, Zr-, and Cu-Catalyzed Strategy for Enantioselective Synthesis of Alkenyl-Substituted Quaternary Carbons
作者:Kevin P. McGrath、Amir H. Hoveyda
DOI:10.1002/anie.201407837
日期:2014.10.6
Features of the chromatography-mass spectrometric identification of condensation products of the carbonyl compounds
作者:I. G. Zenkevich、A. I. Ukolov
DOI:10.1134/s1070363211090143
日期:2011.9
By the example of the condensation products of acetone with the simplest aromatic carbonyl compounds it was shown that the joint interpretation of mass spectrometric and chromatographic data in conjunction with a priori assumptions about the nature of the chemical structure allows the detection of the components of reaction mixtures that were not previously characterized by standard mass spectra or by retention indices on standard stationary phases. A necessary condition for solving such problems is creating a hypothesis about the sample composition that is possible for the expected products of the known organic reactions.