59793-79-2

Upstream product

• 3282-30-2 pivaloyl chloride 
• 24856-58-4 1,1-dimethoxy-1-(4-bromophenyl)methane 
• 1357256-02-0 C₁₄H₂₀O₃ 
• 23281-56-3 1,3-dimethyl-2-(4-chlorophenyl)imidazolidine 
• 104-88-1 4-chlorobenzaldehyde 

Relevant academic research and scientific papers

Methodology for in situ protection of aldehydes and ketones using trimethylsilyl trifluoromethanesulfonate and phosphines: Selective alkylation and reduction of ketones, esters, amides, and nitriles

A methodology for selective transformations of ketones, esters, Weinreb amides, and nitriles in the presence of aldehydes has been developed. The use of a combination of PPh3-trimethylsilyl trifluoromethanesulfonate (TMSOTf) promotes selective transformation of aldehydes to their corresponding, temporarily protected, O,P-acetal type phosphonium salts. Because, hydrolytic work-up following ensuing reactions of other carbonyl moieties in the substrates liberates the aldehyde moiety, a sequence involving aldehyde protection, transformation of other carbonyl groups, and deprotection can be accomplished in a one-pot manner. Furthermore, the use of PEt3 instead of PPh 3 enables ketones to be converted in situ to their corresponding O,P-ketal type phosphonium salts and, consequently, selective transformations of esters, Weinreb amides, and nitriles in the presence of ketones can be performed. This methodology is applicable to various dicarbonyl compounds, including substrates that possess heteroaromatic skeletons and hydroxyl protecting groups.

Reversing the reactivity of carbonyl functions with phosphonium salts: Enantioselective total synthesis of (+)-centrolobine

Step saver: Carbonyl groups with lower reactivities can be transformed in the presence of more reactive ones by treatment with PPh3 (or PEt3) and TMSOTf prior to the reaction (see scheme; TMS=trimethylsilyl, Tf=trifluoromethanesulfonyl). This methodology can be applied to reduction and alkylation reactions, and enabled the short asymmetric total synthesis of (+)-centrolobine with the highest overall yield reported to date.

Reductive lithiation of 1,3-dimethyl-2-arylimidazolidines

Naphthalene catalyzed lithiation of 1,3-dimethyl-2-phenylimidazolidine led to cleavage of the benzylic carbon-nitrogen bond, with formation of an intermediate dianion. Under similar conditions, 1,3-dimethyl-2-(4-chlorophenyl) imidazolidine underwent regioselective cleavage of the aromatic carbon-chlorine bond, leading to a 4-formylphenyllithium equivalent, whilst 1,3-dimethyl-2-(4- methoxymethylphenyl)imidazolidine underwent regioselective cleavage of the benzylic carbon-oxygen bond, leading to a 4-formylbenzyllithium equivalent.

1-(P-Alkanoylphenyl) alkanols and derivatives

1-(p-alkanoylphenyl) alkanols, e.g., 1-(p-acetophenyl)-2,2-dimethylpropanol, are prepared from p-alkanoylphenyl Grignard reagents and alkyl and aryl aldehydes or acyl or aroyl halides and are useful as hypolipidemic and anti-diabetic agents.