40394-90-9Relevant academic research and scientific papers
The Thiazolium-Catalyzed Sila-Stetter Reaction: Conjugate Addition of Acylsilanes to Unsaturated Esters and Ketones
Mattson, Anita E.,Bharadwaj, Ashwin R.,Scheidt, Karl A.
, p. 2314 - 2315 (2004)
A new acyl anion addition reaction between acylsilanes and α,β-unsaturated conjugate acceptors promoted by a nucleophilic organic catalyst has been disclosed. The 1,4-dicarbonyl products produced in this reaction are highly useful synthons. Neutral carbenes (or zwitterions) generated in situ from commercial thiazolium salts are used as effective catalysts for the reaction which is in contrast to established anionic catalysts typically employed to promote the required Brook rearrangement (1,2-silyl shift from carbon to oxygen) involved in the reported reaction. This process successfully utilizes acylsilanes as tunable acyl anion progenitors and is tolerant of a wide range of structural diversity on the acylsilane or the conjugate acceptor. Copyright
Thiazolium-catalyzed additions of acylsilanes: A general strategy for acyl anion addition reactions
Mattson, Anita E.,Bharadwaj, Ashwin R.,Zuhl, Andrea M.,Scheidt, Karl A.
, p. 5715 - 5724 (2007/10/03)
A strategy utilizing N-heterocyclic carbenes (NHCs) derived from thiazolium salts has been developed for the generation of carbonyl anions from acylsilanes. Synthetically useful 1,4-diketones and N-phosphinoyl-α- aminoketones have been prepared in good to excellent yields via NHC-catalyzed additions of acylsilanes to the corresponding α,β-unsaturated systems and N-phosphinoylimines. These organocatalytic reactions are air- and water-tolerant methods to execute robust carbonyl anion addition reactions. Additionally, polysubstituted aromatic furans and pyrroles have been efficiently synthesized in a one-pot process using this carbonyl anion methodology. The addition of alcohols to the reaction renders the process catalytic in thiazolium salt. In an effort to synthesize a potential intermediate along the proposed reaction pathway, silylated thiazolium carbinols have been identified to provide good yields of carbonyl anion addition products when subjected to the standard reaction conditions in the presence of suitable electrophiles.
Process for preparing ketones
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, (2008/06/13)
Ketones are prepared by reacting an aromatic or heterocyclic aldehyde in the presence of a cyanide ion with an unsaturated compound having the formula (I): STR1 wherein R1, R2 and R3 are the same or different and are selected from the group of hydrogen, optionally substituted aliphatic, cycloaliphatic, araliphatic, aromatic, heterocyclic and carboxylic acid ester and R4 is nitrile (CN), --CO--R5 or --CO--OR5 wherein R5 is selected from the group of optionally substituted aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic and R1 and R2 and/or R1 and R3 and/or R2 and R5 or R3 and R5 together with the carbon atoms to which they are attached as substituents may also form a carbocyclic or heterocyclic ring. Ketones prepared according to the process of the invention have the formula: STR2 wherein R1 ' and R3 ' are identical or different and are selected from the group of hydrogen, lower alkyl having up to 3 C-atoms and optionally substituted phenyl; and R6 ' is optionally substituted phenyl or a pyridyl.
