<i>N</i>-Boc-<i>N</i>-(benzotriazol-1-ylmethyl)benzylamine as a 1,1-Dipole Equivalent in Stereoselective Synthesis of 4,5-Disubstituted Imidazolidin-2-ones

Katritzky, Alan R.; Luo, Zhushou; Fang, Yunfeng; Steel, Peter J.

doi:10.1021/jo001615h

Cited by 29 publications

(12 citation statements)

References 32 publications

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“…N-Boc-benzylamine [146] reacted with formaldehyde and benzotriazole to furnish N-Boc-N-(benzotriazolylmethyl)benzylamine 190, which upon treatment with sec-butyllithium followed by the addition of imines gave benzotriazolylimidazolidinone derivatives 191. Subsequent treatment of 191 with nucleophiles provided products 192 stereoselectively keeping the trans-relative stereochemistry of the substituents on C-4 and C-5 of the starting material (Scheme 70) [147]. When the Vilsmeier-type salt 145 [121] is treated with triethylamine, it generated an aminocarbene, which underwent [1+2+2] cycloaddition with phenylisocyanate to give imidazolidine-2,4-diones 193.…”

Section: Imidazolidinonesmentioning

confidence: 99%

Benzotriazole-Mediated Synthesis of Nitrogen-Containing Heterocycles

Beagle

2015

Topics in Heterocyclic Chemistry

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Application of benzotriazole methodology for the preparation of nitrogen-containing heterocyclic compounds is summarized in this review. The characteristic advantages of benzotriazole are first briefly considered followed by an overview of its use in the synthesis of heterocycles organized by the ring size. Finally, the use of benzotriazole in the synthesis of bicyclic systems is showcased in only selected examples.

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Section: Imidazolidinonesmentioning

confidence: 99%

Benzotriazole-Mediated Synthesis of Nitrogen-Containing Heterocycles

Beagle

2015

Topics in Heterocyclic Chemistry

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“…The possibility to remove the N-substituents allows for the preparation of highly enantioenriched amino acids and peptide-building blocks. In N-Boc-N-(benzotriazol-1-ylmethyl)benzylamine, the deprotonation occurs regioselectively at the carbon bonded to the benzotriazolyl group in the presence of s-BuLi (Scheme 7.39) [50]. The lithiated intermediates behave as a 1,1-dipole equivalent that reacts with carbonyl compounds or imines to give 4,5-disubstituted imidazolidin-2-ones.…”

Section: Lithiation Of Acyclic Aminesmentioning

confidence: 99%

Nitrogen‐Bearing Lithium Compounds in Modern Synthesis

Degennaro¹,

Musio²,

Luisi³

2014

Lithium Compounds in Organic Synthesis

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IntroductionNitrogen-containing compounds are ubiquitous and are extremely important in synthesis. This chapter reports some general aspects of the generation, structure, and reactivity of nitrogen-bearing organolithiums showing the progress made over the last decade. The chapter does not cover comprehensively the field but the aim is to provide the reader with useful information on the generation, reactivity, and potential in synthesis of this kind of lithiated intermediates.Throughout the chapter, the name amino-organolithiums is used to describe reactive intermediates lithiated at sp 3 -hybridized carbon atoms adjacent (α) to a nitrogen atom that could be included also in a ring. Amino-organolithiums can be generated mainly in three different ways: (i) deprotonation of a parent amine or its derivative; (ii) transmetallation by using an alkyllithium; and (iii) reductive cleavage of C-heteroatom bond (e.g., C-S). Each way has advantages and disadvantages and in some cases they complement each other (Scheme 7.1).Direct deprotonation is a widely used strategy to generate amino-organolithiums even in chiral form, while tin-lithium exchange reactions are preferred when direct deprotonations are difficult (high kinetic barrier) or regiochemical issues apply. Concerning the direct deprotonation of amines, this is not a simple task because the corresponding lithiated intermediates suffer from destabilizing interactions that make this reaction very difficult unless a ''stabilizing group'' (SG) is introduced either on the nitrogen atom or on the lithium-bearing carbon (Scheme 7.2).The SG (Scheme 7.2) has a pivotal role, either reducing the kinetic barrier in the hydrogen/lithium permutation or stabilizing the organolithium mesomerically or by coordination. For these reasons, often, amino-organolithiums are classified as stabilized or unstabilized. The chemistry of unstabilized amino-organolithiums has been so far less developed however, lithiation of simple tertiary amines could be accomplished by two main strategies: (i) by tin/lithium exchange reaction and (ii) by deprotonation of quaternary ammonium complexes (Scheme 7.3).

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“…Treating amine 306 with s-BuLi and subsequently with an aldimine or an aldehyde, affords imidazolidinones or oxazolidinones bearing a benzotriazolyl group on C4. With imidazolidinones 307 it is possible to substitute the benzotriazolyl group with various C-nucleophiles to obtain differently substituted imidazolinones (Scheme 10.176) [484].…”

Section: 56mentioning

confidence: 99%