77902-87-5

Upstream product

• 123-75-1 pyrrolidine 
• 3282-30-2 pivaloyl chloride 
• 3389-55-7 2,2-dimethyl-1-(pyrrolidin-1-yl)propan-1-one 

Downstream Products

• 77902-92-2 Benzyl γ,γ-dimethyl-β-oxovalerate 

Relevant academic research and scientific papers

Ligand-Enabled Enantioselective Csp3 –H Activation of Tetrahydroquinolines and Saturated Aza-Heterocycles by RhI

The first rhodium(I)-catalyzed enantioselective intermolecular C (Formula presented.) –H activation of various saturated aza-heterocycles including tetrahydroquinolines, piperidines, piperazines, azetidines, pyrrolidines, and azepanes is presented. The combination of a rhodium(I) precatalyst and a chiral monodentate phosphonite ligand is shown to be a powerful catalytic system to access a variety of important enantio-enriched heterocycles from simple starting materials. Notably, the C (Formula presented.) –H activation of tetrahydroquinolines is especially challenging due to the adjacent C (Formula presented.) ?H bond. This redox-neutral methodology provides a new synthetic route to α-N-arylated heterocycles with high chemoselectivity and enantioselectivity up to 97 % ee.

Thioamide-Directed Cobalt(III)-Catalyzed Selective Amidation of C(sp3)?H Bonds

A mild, oxidant-free, and selective Cp*CoIII-catalyzed amidation of thioamides with robust dioxazolone amidating agents via C(sp3)?H bond activation to generate the desired amidated products is reported. The method is efficient and allows for the C?H amidation of a wide range of functionalized thioamides with aryl-, heteroaryl-, and alkyl-substituted dioxazolones under the Cp*CoIII-catalyzed conditions. The observed regioselectivity towards primary C(sp3)?H activation is supported by computational studies and the cyclometalation is proposed to proceed by means of an external carboxylate-assisted concerted metalation/deprotonation mechanism. The reported method is a rare example of the use of a directing group other than the commonly used pyridine and quinolone classes for Cp*CoIII-catalyzed C(sp3)?H functionalization and the first to exploit thioamides.

Mechanistic interrogation of the asymmetric lithiation-trapping of N-thiopivaloyl azetidine and pyrrolidine

A fundamental mechanistic study of the s-BuLi/chiral diamine-mediated lithiation-trapping of N-thiopivaloyl azetidine and pyrrolidine is reported. We show that lithiated thiopivalamides are configurationally unstable at -78 °C. Reaction then proceeds via a dynamic resolution of diastereomeric lithiated intermediates and this accounts for the variable sense and degree of asymmetric induction observed compared to N-Boc heterocycles.

α-Arylation of Saturated Azacycles and N-Methylamines via Palladium(II)-Catalyzed C(sp3)-H Coupling

Pd(II)-catalyzed α-C(sp3)-H arylation of pyrrolidines, piperidines, azepanes, and N-methylamines with arylboronic acids has been developed for the first time. This transformation is applicable to wide arrays of pyrrolidines and boronic acids, including heteroaromatic boronic acids. A diastereoselective one-pot heterodiarylation of pyrrolidines has also been achieved.

A new efficient synthesis of α-methyl-β-ketoesters through an Eschenmoser sulfide reaction

Various α-methyl-β-ketoesters were readily synthesized through Eschenmoser condensation of thioamides with a commercially available bromoester. β-Enaminoesters were easily prepared through this sulfide contraction reaction and were hydrolysed to afford the corresponding β-ketoesters in moderate to good yields.

A Facile Conversion of Amides and Lactams to Thioamides and Thiolactams using Tetrathiomolybdate

Chloro iminium salts generated in situ from amides and lactams using (COCl)2 or POCl3 reacted very readily with the new sulfur transfer reagent, benzyltriethylammonium tetrathiomolybdate to afford the corresponding thioamides and thiolactams in excellent yields under mild reaction conditions.

Conversion of Amides and Lactams to Thioamides and Thiolactams Using Hexamethyldisilathiane

Amides and lactams were converted to their corresponding thioamides and thiolactams employing a new protocol using hexamethyldisilathiane (TMS2S).Oxophilic promoters were employed to generate Vilsmeier-type intermediates, the most efficient reagents being phosphorus oxychloride, triphosgene, and oxalyl chloride.Thionation of intermediate chloro iminium ions was accomplished in situ with TMS2S.Yields were good to excellent for secondary and tertiary amides and lactams while yields for primary systems were poor.

Versatile β-Keto Ester and β-Keto Nitrile Synthesis through Sulfide Contraction.

A versatile and efficient synthesis for various β-keto esters, including those which are α substituted, is described.The α-thio iminium salt prepared from a thioamide and a primary or secondary alkylating agent is subjected to sulfur extrusion upon addition of base and a phosphine thiophile, and the result is an enamino ester which may be hydrolyzed to the desired β-keto ester.The method is also applicable to the preparation of various substituted β-keto nitriles.