Carbenium ion trapping using sulfonamides: an acid-catalysed synthesis of pyrrolidines by intramolecular hydroamination

Griffiths‐Jones, Charlotte M.; Knight, David W.

doi:10.1016/j.tet.2010.03.107

Cited by 27 publications

(2 citation statements)

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“…The research group of David W. Knight made further step on elaborating methods for the construction of the discussed topology. 25,26 Thus, exploiting G. Stork procedure for the generation of   -unsaturated N-Ts-protected amino acids, 27 they involved the latter into triflic acid induced 5-endo-trig cyclization to give a desired spiro proline (Figure 2, B). The same ring closure can also be accomplished as 5-endoiodocyclisations, though requiring much more time for the reaction to be completed.…”

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confidence: 99%

CONCISE AND PRACTICAL AVENUES TO 5,5-Spiro-Α-Prolines

Iermolenko,

Artemenko,

Vasko

et al. 2024

Preprint

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Scaffold hopping and three-dimensionality are one of dominating notions in contemporary drug discovery process. Following these concepts is a verified and generally robust avenue to improve the biological activity of a lead against a protein target, selectivity issues as well as ADMET properties. Unfortunately, the freedom of medicinal chemists to replace molecular fragments responsible for the properties is restricted due to unrevealed areas of chemical space existing for even simple building blocks. This paper contributes to the support of drug discovery workflow and describes concise and practical synthetic approaches toward multigram preparation of value-added conformationally constrained 5-spirocyclic α-prolines from readily accessible starting materials. Direct carboxylation of 2-spiropyrrolidines was found to be a novel and promising approach to achieve the purpose and is the most fruitful for substrates with no acidic centers within a part spiro linked to pyrrolidine core. The method allows for quick and one-step preparation of the target chemicals in good yields. For substrates inapplicable to the straightforward method, an alternative synthetic avenue was designed. This 4-steps protocol deals with common for laboratory practice transformations and is comparable in its efficiency with the carboxylation method. The paper concludes a series of our works on the elaboration of efficient methods for the construction of spiro proline frameworks.

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Section: Figure 1 Background Of the Workmentioning

confidence: 99%

CONCISE AND PRACTICAL AVENUES TO 5,5-Spiro-Α-Prolines

Iermolenko,

Artemenko,

Vasko

et al. 2024

Preprint

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“…One notable example is finasteride, which stands as the first clinically approved inhibitor of the steroid 5α-reductase type II. It is used for the treatment of benign prostatic hyperplasia and male pattern hair loss. , …”

Section: Introductionmentioning

confidence: 99%

Iridium Acylnitrenoid-Initiated Biomimetic Cascade Cyclizations: Stereodefined Access to Polycyclic δ-Lactams

Tufano,

Lee,

Barilli

et al. 2023

J. Am. Chem. Soc.

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Ring-fused azacyclic compounds are important building units in the synthesis of biorelevant natural products, pharmaceutical agents, and molecular materials. Herein, we present a new approach to these condensed azacycles by a biomimetic cascade cyclization of arylalkenyl dioxazolones. This cascade reaction was found to proceed with excellent stereoselectivity and a high functional group tolerance. The substrate scope of arylalkenyl dioxazolones turned out to be highly flexible and extendable to additional terminating subunits, such as heteroaryl and alkynyl moieties. This biomimetic cyclization was elucidated to be initiated by an intramolecular transfer of the in situ generated electrophilic Ir-acylnitrenoid to the tethered olefinic double bond, leading to a key N-acylaziridine intermediate, which is in turn reacted with pendant (hetero)arenes or alkynes in a highly regio- and stereoselective manner to produce ring-fused azacyclic compounds.

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Hydroamination of Alkenes

Reznichenko

Hultzsch

2015

Organic Reactions

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The addition of an amine NH‐functionality to alkenes (including vinyl arenes, conjugated dienes, allenes or ring‐strained alkenes), the so‐called hydroamination, represents a simple and highly atom‐economical approach for the synthesis of nitrogen‐containing products. A large variety of catalyst systems are available, ranging from alkali, alkaline earth, rare earth, Group 4 and Group 5 metals, to late transition metal catalysts, and, less prominent, Brønsted and Lewis acid‐based catalyst systems. The mode of operation of these catalyst systems can vary significantly and the different reaction mechanisms and the scope and limitations are discussed. While intramolecular hydroamination reactions can be readily achieved with a large number of catalyst systems, significantly fewer examples for the more challenging intermolecular hydroamination are known, especially for unactivated alkenes. The stereoselective hydroamination has also received significant attention due to the importance of chiral nitrogen‐containing molecules in pharmaceutical industry. A variety of highly selective chiral catalyst systems have been developed for intramolecular hydroaminations, while examples of intermolecular asymmetric hydroaminations are scarce. Hydroamination in the context of this review article is defined as the addition of HNR 2 across a non‐activated, unsaturated carbon‐carbon multiple bond. This review focuses on the hydroamination reaction of simple, non‐activated alkenes. The addition of amines to slightly activated alkenes, such as vinyl arenes, 1,3‐dienes, strained alkenes (norbornene derivatives, methylenecyclopropenes) and allenes is closely related and is covered as well. However, hydroamination reactions of alkynes and Aza‐Michael reactions involving the addition of an N‐H fragment across the conjugated or otherwise activated double bond of a Michael acceptor are not covered. The scope of amine types includes ammonia, primary and secondary aliphatic and aromatic amines, azoles, and hydrazines. N ‐Protected amines, such as ureas, carboxamides, and sulfonamides are covered as well, as they are important substrates for metal‐free and late transition metal‐based catalysts. The literature through January 2011 will be covered with two selected references from 2012 (comprising Table 3D). A supplemental reference list is provided for reports appearing February 2011 through April 2015. The chapter is organized by the nature of the carbon unsaturation to which the amine is added. Ranging from less reactive substrates such as ethylene and unactivated alkenes, to slightly activated substrates, such as vinyl arenes, and more activated substrates, including conjugated dienes, allenes and strained alkenes. Enantioselective hydroamination reactions, an area that has seen significant progress over the past decade, are discussed next. Finally, tandem hydroamination/carbocyclization reactions of aminodialkenes provide rapid access to complex alkaloidal skeletons. The tables at the end of the chapter are separated into five main sections: achiral intermolecular hydroamination, achiral intramolecular hydroamination, enantioselective intermolecular hydroamination, enantioselective intramolecular hydroamination, and tandem hydroamination/carbocyclization. Within the first four sections the tables are further divided into subsections based on the participating alkene, i.e. alkenes, vinyl arenes, dienes, allenes, and strained alkenes.

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Carbenium ion trapping using sulfonamides: an acid-catalysed synthesis of pyrrolidines by intramolecular hydroamination

Cited by 27 publications

References 74 publications

CONCISE AND PRACTICAL AVENUES TO 5,5-Spiro-Α-Prolines

CONCISE AND PRACTICAL AVENUES TO 5,5-Spiro-Α-Prolines

Iridium Acylnitrenoid-Initiated Biomimetic Cascade Cyclizations: Stereodefined Access to Polycyclic δ-Lactams

Hydroamination of Alkenes

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