STUDIES IN THE MANNICH REACTION

A strategy is outlined for the synthesis of loline alkaloids. This second-generation approach features direct access to the requisite vicinal diamino motif by a Cu(OTf)2-mediated highly -diastereoselective vinylogous Mannich reaction (VMR) of Ellman --butanesulfinyl imine derived from isopropylidene-protected ()-glyceraldehyde, with -Boc-2--(butyldimethylsilyloxy)pyrrole (TBSOP). Fleming’s method was employed for the introduction of a hydroxyl group at C4 of the adduct, which gave the undesired diastereomer in 40% yield. The intramolecular SN reaction of the pyrrolizidine derivative to build the etheral bridge proved to be difficult, and produced -Bus-norloline in only 20% yield. In light of the valuable information gained during this investigation, an improved version of the second-generation approach is being investigated, which is expected to provide a concise and efficient access to the challenging loline alkaloids.

Applications of the Mannich reaction

Get this from a library! STUDIES IN THE MANNICH REACTION.. [JACK NULK WELLS]

The Petasis-Borono Mannich Reaction in Glycerol

and for the preparation of Mannich reaction , Acetylenic compounds (3) and (6) were treated with paraformaldehyde in Isopropyl alcohol and the mixture was heated a bit, then added Secondary amine with Copper chloride with continuous heating to obtain derivatives 4a-e and 7a-e. The purpose of the preparation of these derivatives is to get a new uracil derivatives containing acetylenic amines possible to have a biological effectiveness.

//

Ketonic Mannich Bases and the Products of their Reduction and ..

This thesis describes the development of the conjugate addition/nitro-Mannich reaction and its use in the synthesis of useful molecules like pyrrolidin-2-ones and piperazin-2-ones. The introductory chapter of this thesis outlines the literature related to the nitro-Mannich reaction, describing the different existing methodologies for performing the reaction in diastereo- and enantioselective manner. The synthetic applications of the reaction are also described, especially its uses in the synthesis of biologically active natural products. Moreover, the syntheses and uses of two classes of compounds, pyrrolidin-2-ones and piperazin-2-ones are briefly discussed. The results and discussion chapter starts by presenting the use of a one-pot conjugate addition/nitro-Mannich/lactamisation reaction in the synthesis of densely functionalised pyrrolidin-2-ones. The development of an asymmetric protocol, as well as some functionalisations of the pyrrolidinone core are also described. Our efforts to synthesise human neutrophil elastase inhibitor GW311616A using the developed methodology are then detailed. The next part of the results and discussion chapter portrays the development of a conjugate addition/nitro-Mannich reaction of non-zinc nucleophiles to ethyl 3-nitroacrylate and β-nitrostyrene. The scope and limitations of the reaction were investigated using a variety of different nucleophiles including amines, thiols, phosphines, alcohols, enolates and nitriles. Finally, our work towards synthesising the biologically active piperazin-2-one piperazirum, using the nitro-Mannich methodology is described. The diastereoselective synthesis and characterisation of a densely functionalised piperazin-2-one was accomplished. A detailed description of the experimental details and analytical data for all novel compounds is described in the experimental section. Tables of coupling constants and X-ray crystallographic data are presented in the appendices section, followed by a list of literature references.

and for the preparation of Mannich reaction , ..

After difficulties were encountered in a first-generation synthesis plan toward himeradine A, a second-generation synthesis plan was eventually successful in accomplishing the first total synthesis of fastigiatine via a formal [3+3]-cycloaddition reaction and a retro-aldol tandem transannular Mannich reaction sequence.

Last modified: 08/22/2017 Downloadable Content

A strategy is outlined for the synthesis of loline alkaloids. This second-generation approach features direct access to the requisite vicinal diamino motif by a Cu(OTf)2-mediated highly -diastereoselective vinylogous Mannich reaction (VMR) of Ellman --butanesulfinyl imine derived from isopropylidene-protected ()-glyceraldehyde, with -Boc-2--(butyldimethylsilyloxy)pyrrole (TBSOP). Fleming’s method was employed for the introduction of a hydroxyl group at C4 of the adduct, which gave the undesired diastereomer in 40% yield. The intramolecular SN reaction of the pyrrolizidine derivative to build the etheral bridge proved to be difficult, and produced -Bus-norloline in only 20% yield. In light of the valuable information gained during this investigation, an improved version of the second-generation approach is being investigated, which is expected to provide a concise and efficient access to the challenging loline alkaloids.

Bioinorganic Chemistry and Applications is a peer-reviewed, ..

Stereoselective Synthesis of 1(S)‐ Camphor‐2‐cis‐methylidene Isocyanide and Its Application.
Multicomponent Coupling Reactions for Organic Synthesis: Chemoselective Reactions with The best known classical multicomponent reaction PhD thesis.
This thesis presents a work in the field of multicomponent reactions (MCRs), one-step condensation between a fluorous tagged aldehyde, β-keto ester and urea derivatives.
Thesis available for immediate download.