- Chemoselective Intermolecular Cross-Enolate-Type Coupling of Amides
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A new approach for the synthesis of 1,4-dicarbonyl compounds is reported. Chemoselective activation of amide carbonyl functionality and subsequent umpolung via N-oxide addition generates an electrophilic enolonium species that can be coupled with a wide range of nucleophilic enolates. The method conveys broad functional group tolerance on both components, does not suffer from formation of homocoupling byproducts and avoids the use of transition metal catalysts.
- Kaiser, Daniel,Teskey, Christopher J.,Adler, Pauline,Maulide, Nuno
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- A General Acid-Mediated Hydroaminomethylation of Unactivated Alkenes and Alkynes
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In comparison to the extensively studied metal-catalyzed hydroamination reaction, hydroaminomethylation has received significantly less attention despite its considerable potential to streamline amine synthesis. State-of-the-art protocols for hydroaminomethylation of alkenes rely largely on transition-metal catalysis, enabling this transformation only under highly designed and controlled conditions. Here we report a broadly applicable, acid-mediated approach to the hydroaminomethylation of unactivated alkenes and alkynes. This methodology employs cheap, readily available, and bench-stable reactants and affords the desired amines with excellent functional group tolerance and impeccable regioselectivity. The broad scope of this transformation, as well as mechanistic investigations and in situ domino functionalization reactions are reported.
- Kaiser, Daniel,Tona, Veronica,Gon?alves, Carlos R.,Shaaban, Saad,Oppedisano, Alberto,Maulide, Nuno
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supporting information
p. 14639 - 14643
(2019/09/17)
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- PRODUCTION OF AMINES VIA A HYDROAMINOALKYLATION REACTION
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Provided is a process for producing an amine via a hydroaminoalkylation reaction of a non-aromatic C-C double bond or C-C triple bond, said process comprising a step of reacting a compound comprising a non-aromatic C-C double bond or C-C triple bond with a reactive component which is obtainable by combining an aminal or a hemiaminal ether with an acidic medium comprising trifluoroacetic acid, wherein the aminal contains two amino groups independently selected from a secondary and a tertiary amino group that are linked by a methylene group wherein one hydrogen atom may be replaced by a further substituent, and at least one of the amino groups carries a hydrogen atom at a carbon atom bound in α-position to its nitrogen atom, and the hemiaminal ether contains a secondary or a tertiary amino group which carries a hydrogen atom at a carbon atom bound in α-position to its nitrogen atom, and the secondary or tertiary amino group is linked to an alkoxy group by a methylene group wherein one hydrogen atom may be replaced by a further substituent.
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Page/Page column 60-61
(2019/12/04)
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- Unified Approach to the Chemoselective α-Functionalization of Amides with Heteroatom Nucleophiles
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Functionalization at the α-position of carbonyl compounds has classically relied on enolate chemistry. As a result, the generation of a new C-X bond, where X is more electronegative than carbon requires an oxidation event. Herein we show that, by rendering the α-position of amides electrophilic through a mild and chemoselective umpolung transformation, a broad range of widely available oxygen, nitrogen, sulfur, and halogen nucleophiles can be used to generate α-functionalized amides. More than 60 examples are presented to establish the generality of this process, and calculations of the mechanistic aspects underline a fragmentation pathway that accounts for the broadness of this methodology.
- Gon?alves, Carlos R.,Lemmerer, Miran,Teskey, Christopher J.,Adler, Pauline,Kaiser, Daniel,Maryasin, Boris,González, Leticia,Maulide, Nuno
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supporting information
p. 18437 - 18443
(2019/11/21)
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- Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
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An efficient, broadly applicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields. This method notably enables an easy cleavage of oxazolidinone-based auxiliaries.
- Guissart, Céline,Barros, Andre,Rosa Barata, Luis,Evano, Gwilherm
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p. 5098 - 5102
(2018/09/13)
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- Flexible and Chemoselective Oxidation of Amides to α-Keto Amides and α-Hydroxy Amides
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A suite of flexible and chemoselective methods for the transition-metal-free oxidation of amides to α-keto amides and α-hydroxy amides is presented. These highly valuable motifs are accessed in good to excellent yields and stereoselectivities with high functional group tolerance. The utility of the method is showcased by the formal synthesis of a potent histone deacetylase inhibitor.
- De La Torre, Aurélien,Kaiser, Daniel,Maulide, Nuno
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supporting information
p. 6578 - 6581
(2017/05/29)
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- Cu-Catalyzed cascades to carbocycles: Union of diaryliodonium salts with alkenes or alkynes exploiting remote carbocations
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Copper-catalyzed cascade reactions between alkenes or alkynes and diaryliodonium salts form carbocyclic products in a single step. Arylation of the unsaturated functional group is proposed to form a carbocation intermediate that facilitates hydride shift pathways to translocate the positive charge to a remote position and enables ring formation via a Friedel-Crafts-type reaction.
- Zhang, Fengzhi,Das, Shoubhik,Walkinshaw, Andrew J.,Casitas, Alicia,Taylor, Michael,Suero, Marcos G.,Gaunt, Matthew J.
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supporting information
p. 8851 - 8854
(2014/07/08)
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