Ring-opening reaction of Bus- and SES-protected aziridines using lithiated dithianes

Sakakibara, Ken; Nozaki, Kyoko

doi:10.1039/b814413c

Cited by 7 publications

(4 citation statements)

References 38 publications

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“…In order to investigate further the use of carbon nucleophiles, the 2-nitrobenzenesulfonyl (Ns) group was replaced with the tert -butylsulfonyl (Bus) group, as the nitro groups would not be compatible with hard carbon nucleophiles. This protecting group was chosen over the 4-toluenesulfonyl group (Ts) because it can easily be removed under mildly acidic conditions . However, tert -butylsulfonyl chloride is unstable; therefore, the protecting group had to be synthesized.…”

Section: Resultsmentioning

confidence: 99%

“…N-((2R,3R)-1-((tert-Butyldimethylsilyl)oxy)-3-methyl-3-phenoxyhex-4-yn-2-yl)-2-nitrobenzenesulfonamide (46). Aziridine 21 (46.7 mg, 0.110 mmol) and phenol (21.0 mg, 0.220 mmol) were placed in a flask and dissolved in dry PhCH 3 (1.1 mL).…”

Section: ■ Author Informationmentioning

confidence: 99%

“…This protecting group was chosen over the 4-toluenesulfonyl group (Ts) because it can easily be removed under mildly acidic conditions. 46 However, tert-butylsulfonyl chloride is unstable; therefore, the protecting group had to be synthesized. Using intermediate 8, 2 removal of the Ns group gave the free amine 9, followed by reaction with tert-butylsulfinyl chloride, to produce 10 as a mixture of diastereomers.…”

Section: ■ Introductionmentioning

confidence: 99%

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Possible Reason for the Unusual Regioselectivity in Nucleophilic Ring Opening of Trisubstituted Aziridines under Mildly Basic Conditions

2014

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2,2,3-Trisubstituted aziridines are known to undergo ring opening at the more substituted carbon under mildly basic conditions. However, the reason for the formation of the more sterically encumbered product has never been examined. Several trisubstituted aziridines, with different substitution patterns at the C-2 and C-3 carbons, were synthesized to change the electronics of the aziridine ring system. These changes had no effect on the regioselectivity of the ring-opening reaction. Using the B3LYP/6-31G* DFT basis set it was determined that the transition state for opening at the more substituted carbon proceeds at a lower energy than the transition state at the less substituted carbon.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Author Informationmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

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Possible Reason for the Unusual Regioselectivity in Nucleophilic Ring Opening of Trisubstituted Aziridines under Mildly Basic Conditions

2014

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“…It is well-known that N -arylsulfonylaziridines are highly activated for ring-opening reactions with nucleophiles, − but the cleavage of the resulting sulfonamides is usually difficult and the usually required drastic conditions are uncompatible with several functionalities. This has been addressed using other deprotection alternatives − and a generation of sulfonyl groups. − One of these groups, 2-naphthalenesulfonamide, which combines the efficient activation with milder deprotection conditions, was selected when N -acylaziridines were not active enough to carry out the desired ring-opening reactions.…”

Section: Resultsmentioning

confidence: 99%

Aziridine Ring Opening for the Synthesis of Sphingolipid Analogues: Inhibitors of Sphingolipid-Metabolizing Enzymes

Alcaide

Llebaría

2014

J. Org. Chem.

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A library of sphingolipid analogues is designed and tested as inhibitors against mammalian and fungal sphingolipid enzymes. The synthesis of sphingolipid analogues is based on the nucleophilic ring-opening reactions of N-activated aziridine derivatives with thiols, β-thioglycosyl thiols, phosphorothioates, phosphates, and amines to afford compounds having different lipid backbones and substituents representative of the naturally occurring sphingolipid families. The screening on mammalian sphingomyelin synthase (SMS) and glucosylceramide synthase (GCS) and yeast inositol phosphorylceramide synthase (IPCS) enzymes identified several inhibitors of GCS and IPCS, but no inhibition of SMS was observed among the tested compounds.

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Synthesis of Pyrrolidones and Caprolactams by Intramolecular Cyclization of Linear Precursors

Arthur

Chenault

2021

Handbook of Pyrrolidone and Caprolactam Based Materials

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Pyrrolidones and caprolactams are important molecules, serving functions ranging from their use as solvents and surfactants to their occurrence in natural products and drugs. This chapter is devoted to the synthesis of pyrrolidones and caprolactams by intramolecular ring‐forming reactions. Perhaps the simplest heterolytic cyclization to envision is the attack of an amine group onto a carboxylic acid derivative, forming the amide C–N linkage. Pyrrolidones can be created by carboxamide radical cyclization onto an alkene. Amidyl radicals can activate remote C–H bonds to cyclization. The chapter presents the synthesis of pyrrolidones and caprolactams by homolytic (radical), carbene insertion and metathetic cyclization reactions. Carbenoid attack on an electron‐rich aromatic ring competes favorably with insertion into alkane C–H. Olefin metathesis is a metal‐catalyzed reaction that entails the redistribution of alkene carbons by the scission and regeneration of carbon–carbon double bonds.

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Ring-opening reaction of Bus- and SES-protected aziridines using lithiated dithianes

Cited by 7 publications

References 38 publications

Possible Reason for the Unusual Regioselectivity in Nucleophilic Ring Opening of Trisubstituted Aziridines under Mildly Basic Conditions

Possible Reason for the Unusual Regioselectivity in Nucleophilic Ring Opening of Trisubstituted Aziridines under Mildly Basic Conditions

Aziridine Ring Opening for the Synthesis of Sphingolipid Analogues: Inhibitors of Sphingolipid-Metabolizing Enzymes

Synthesis of Pyrrolidones and Caprolactams by Intramolecular Cyclization of Linear Precursors

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