Research of gold catalyzed reactions

The main focus of the current dissertation thesis is research of gold catalyzed reactions. I was using mass spectrometry as the primary research technique. I complemented the results with infrared multiphoton dissociation spectroscopy, nuclear magnetic resonance spectroscopy and quantum chemical calculations. I have investigated the interaction of the gold(I) cation with unsaturated hydrocarbons in the first part of my thesis. Secondly, I have studied gold(I) or silver(I) affinity to gold acetylides. In the last part, I have investigated the reaction mechanism of a gold mediated addition of methanol to alkynes. I found out that the gold(I) cation interacts stronger with gold acetylides than with nonactivated triple CC bonds. I showed that the complexes containing two gold atoms represent the key intermediates in the mechanism of addition of methanol to alkynes and that the ligand on the gold catalyst plays a fundamental role in the determination of the mechanism. Powered by TCPDF (www.tcpdf.org

Why can a gold salt react as a base?

See the paper

Bambusurils as a mechanistic tool for probing anion effects

Item does not contain fulltextBambusuril macrocycles have high affinity towards anions (X−) such as PF6− and SbF6− or BF4− and ClO4−. Therefore, addition of bambusurils to reaction mixtures containing these anions effectively removes the free anions from the reaction process. Hence, comparing reactions with and without addition of bambusurils can demonstrate whether the anions actively participate in the reaction mechanism or not. We show this approach for gold(i) mediated addition of methanol to an alkyne. The reaction mechanism can proceed via monoaurated intermediates (e.g., in catalysis with [(IPr)AuX]) or via diaurated intermediates (e.g., in catalysis with [(PPh3)AuX]). We show that anions X− slightly affect the reaction rates, however the effect stays almost the same even after their encapsulation in the cavity of bambusurils. We also demonstrate that X− affects the overall reaction rate in the very same way as the reaction rate of the protodeauration step. All results are consistent with the indirect effect of X− by the acidity of the conjugated acid HX on the rate-determining step. There is no evidence that a direct involvement of X− would affect the reaction rate

Correction: Synergistic formal ring contraction for the enantioselective synthesis of spiropyrazolones (Chemical Science (2018) 9 (6368-6373) DOI: 10.1039/C8SC00913A)

The authors regret that a citation related to a previous Michael addition/Trost allylation cascade reaction was omitted at the end of the sentence beginning "With the advent of organocatalysis." The full reference is presented herein as ref. 1. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.</p

correction synergistic formal ring contraction for the enantioselective synthesis of spiropyrazolones

Correction for 'Synergistic formal ring contraction for the enantioselective synthesis of spiropyrazolones' by Marta Meazza et al., Chem. Sci., 2018, 9, 6368–6373

A CuI/CuIII prototypical organometallic mechanism for the deactivation of an active pincer-like CuI catalyst in Ullmann-type couplings

See the paper.Funded under Horizon2020. This article has been published in Chemical Communications, a journal of the Royal Society of Chemistry, see http://pubs.rsc.org/en/content/articlelanding/2017/cc/c7cc04491g#!divAbstract This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence