85390-58-5Relevant academic research and scientific papers
Rhodium(III)-Catalyzed Synthesis of Skipped Enynes via C(sp3)–H Alkynylation of Terminal Alkenes
Della-Felice, Franco,Zanini, Margherita,Jie, Xiaoming,Tan, Eric,Echavarren, Antonio M.
supporting information, p. 5693 - 5698 (2021/02/09)
The RhIII-catalyzed allylic C?H alkynylation of non-activated terminal alkenes leads selectively to linear 1,4-enynes at room-temperature. The catalytic system tolerates a wide range of functional groups without competing functionalization at other positions. Similarly, the vinylic C?H alkynylation of α,β- and β,γ- unsaturated amides gives conjugated Z-1,3-enynes and E-enediynes.
A practical catalytic reductive amination of carboxylic acids
Andrews, Keith G.,Denton, Ross M.,Hirst, David J.,Stoll, Emma L.,Tongue, Thomas,Valette, Damien
, p. 9494 - 9500 (2020/10/02)
We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles. The two-step reaction exploits the dual reactivity of phenylsilane and involves a silane-mediated amidation followed by a Zn(OAc)2-catalyzed amide reduction. The reaction is applicable to a wide range of amines and carboxylic acids and has been demonstrated on a large scale (305 mmol of amine). The rate differential between the reduction of tertiary and secondary amide intermediates is exemplified in a convergent synthesis of the antiretroviral medicine maraviroc. Mechanistic studies demonstrate that a residual 0.5 equivalents of carboxylic acid from the amidation step is responsible for the generation of silane reductants with augmented reactivity, which allow secondary amides, previously unreactive in zinc/phenylsilane systems, to be reduced.
Lipase-catalyzed amidation of carboxylic acid and amines
Manova, Daniela,Gallier, Florian,Tak-Tak, Lotfi,Yotava, Lyubov,Lubin-Germain, Nadège
supporting information, p. 2086 - 2090 (2018/05/04)
The amidation reaction is of a very particular interest, especially in the pharmaceutical industry and always requires the activation of the acid with a large excess of reactants. Therefore, a large amount of waste is generated. In order to reduce the environmental impact of such reaction, we have developed enzymatic amidation conditions which are compatible with a wide range of amines and acids, in particular with the biologically relevant lipoic acid. Water is the only by-product generated during this reaction thus a very high atom economy is obtained. In addition, we have shown that the lipase can be recovered and reused several times without a significant loss of activity.
Dehydrogenative Allylic Aminations of But-3-enoic Acid Derivatives
Diamante, Daria,Gabrieli, Sara,Benincori, Tiziana,Broggini, Gianluigi,Oble, Julie,Poli, Giovanni
supporting information, p. 3400 - 3412 (2016/09/12)
Two complementary Pd-catalyzed protocols enabling the γ-selective intermolecular allylic amination of but-3-enoic acid derivatives are reported. These transformations can be successfully achieved via either a direct Pd(II)-catalyzed protocol or by way of a one-pot Pd(II)/Pd(0)-catalyzed sequence, depending on the nature of the nitrogen nucleophile used.
Directed, regiocontrolled hydroamination of unactivated alkenes via protodepalladation
Gurak, John A.,Yang, Kin S.,Liu, Zhen,Engle, Keary M.
supporting information, p. 5805 - 5808 (2016/06/09)
A directed, regiocontrolled hydroamination of unactivated terminal and internal alkenes is reported. The reaction is catalyzed by palladium(II) acetate and is compatible with a variety of nitrogen nucleophiles. A removable bidentate directing group is used to control the regiochemistry, prevent β-hydride elimination, and stabilize the nucleopalladated intermediate, facilitating a protodepalladation event. This method affords highly functionalized amino acids in good yields with high regioselectivity.
Pd-catalyzed cross-coupling of potassium alkenyltrifluoroborates with 2-chloroacetates and 2-chloroacetamides
Molander, Gary A.,Barcellos, Thiago,Traister, Kaitlin M.
supporting information, p. 3342 - 3345 (2013/07/26)
A protocol for the stereocontrolled synthesis of (E)- and (Z)-β,γ-unsaturated esters and amides is reported. 2-Chloroacetates as well as secondary and tertiary 2-chloroacetamides were successfully employed as electrophiles in the Suzuki-Miyaura cross-coupling reaction with potassium (E)- and (Z)-alkenyltrifluoroborates, affording the corresponding products in high yield.
XtalFluor-E, an efficient coupling reagent for amidation of carboxylic acids
Orliac, Aurélie,Gomez Pardo, Domingo,Bombrun, Agnès,Cossy, Janine
supporting information, p. 902 - 905 (2013/03/29)
Amides were produced from carboxylic acids and amines by using XtalFluor-E as an activator. Even poorly reactive carboxylic acids can be transformed to amides. In addition, optically active amines and/or carboxylic acids were not epimerized/racemized during the process.
[1,3]-Transfer of chirality during the nicholas reaction in γ-benzyloxy propargylic alcohols
Diaz, David D.,Ramirez, Miguel A.,Martin, Victor S.
, p. 2593 - 2606 (2008/02/07)
A highly regio- and stereoselective intramolecular [1.5]-hydrogentransfer process is described. Treatment of γ-benzyl-protccted Co 2(CO)6-α,γ-acetylenic diols with BF 3·OEt2 provides bis-homopropargylic alcohols. The reaction occurs within seconds, tolerates a wide range of functionalities, and provides good yields. When the ether group is located at a stereochemically defined carbon atom, the rearrangement occurs with high stereoselectivity, transferring the chirality of the carbinol center to the newly created stereocenter. The cleavage of the benzyloxy group is totally regioselective when additional benzyl ethers are present. The scope and limitations of this novel process in densely substituted substrates are evaluated, and possible competitive reactions and/or stereochemical influences are also described. A mechanism based on a highly ordered chair-like transition state substantiated by a theoretical study is also included.
Stereoselective syntheses of substituted 5,6-dihydro-2(1H)-pyridinones in polyphosphate media
Marson,Grabowska,Fallah,Walsgrove,Eggleston,Baures
, p. 291 - 296 (2007/10/02)
δ-Lactams have been synthesized with excellent stereocontrol of substituents by condensing 3-alkenamides with aryl aldehydes in polyphosphoric ester. The scope of the condensation of 3-alkenamides with aryl aldehydes in several phosphate media is examined, and a rationale is proposed regarding γ-lactam versus δ-lactam formation.
A New Synthesis of (R)-GABOB and (R)-Oxiracetam
Orena, Mario,Porzi, Gianni,Sandri, Sergio
, p. 2701 - 2711 (2007/10/02)
The synthesis of both (R)-GABOB 1 and (R)-Oxiracetam 2 through the same diastereomer intermediate 8a is reported.
