Electrophilic Amination Reagents Research Articles

Catalytic enantioselective electrophilic α-hydrazination of β-ketoesters using bifunctional organocatalysts

The catalytic enantioselective electrophilic α-hydrazination promoted by chiral bifunctional organocatalysts is described. Treatment of β-ketoesters with azodicarboxylates as electrophilic amination reagents under mild reaction conditions afforded the corresponding α-amino β-ketoesters with excellent enantiomeric excesses (93–99% ee).

Catalytic Asymmetric Electrophilic α-Amination of α-Cyanoketones in the Presence of Chiral Palladium Complexes

The catalytic enantioselective electrophilic α-amination promoted by chiral palladium complexes is described. Treatment of α-cyanoketones with azodicarboxylates as electrophilic amination reagents under mild reaction conditions afforded the corresponding α-amino α-cyanoketones with excellent enantiomeric excesses (81-95% ee).

Catalytic enantioselective electrophilic α-amination of β-ketoesters catalyzed by chiral palladium complexes

The catalytic enantioselective electrophilic α-amination promoted chiral palladium complexes is described. Treatment of β-ketoesters with azodicarboxylates as electrophilic amination reagents under mild reaction conditions afforded the corresponding α-amino β-ketoesters with excellent enantiomeric excesses (91–99% ee). Palladium complexes were immobilized in [bmim]PF 6, and their applications to catalytic α-amination of β-ketoesters were successfully demonstrated.

Catalytic Enantioselective Fluorination and Amination of β‐Keto Phosphonates Catalyzed by Chiral Palladium Complexes.

The catalytic enantioselective fluorination and amination of β-keto phosphonates catalyzed by chiral palladium complexes is described. Treatment of β-keto phosphonates with N-fluorobenzenesulfonimide (NFSI) as electrophilic fluorinating reagent and diethyl azodicarboxylate (DEAD) as electrophilic amination reagent under mild reaction conditions afforded the corresponding α-substituted β-keto phosphonates in moderate to excellent yields with excellent enantiomeric excesses.

Catalytic Enantioselective Fluorination and Amination of β-Keto Phosphonates Catalyzed by Chiral Palladium Complexes

[reaction: see text] The catalytic enantioselective fluorination and amination of beta-keto phosphonates catalyzed by chiral palladium complexes is described. Treatment of beta-keto phosphonates with N-fluorobenzenesulfonimide (NFSI) as electrophilic fluorinating reagent and diethyl azodicarboxylate (DEAD) as electrophilic amination reagent under mild reaction conditions afforded the corresponding alpha-substituted beta-keto phosphonates in moderate to excellent yields with excellent enantiomeric excesses.

Synthesis of Primary Amines and N‐Methylamines by the Electrophilic Amination of Grignard Reagents with 2‐Imidazolidinone O‐Sulfonyloxime.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Primary Amines and N-Methylamines by the Electrophilic Amination of Grignard Reagents with 2-Imidazolidinone O-Sulfonyloxime

Abstract 2-Imidazolidinone O-sulfonyloxime reacts with various aryl and alkyl Grignard reagents as an electrophilic amination reagent, giving N-alkylated imines. The resulting imines are transformed to primary amines and N-methyl secondary amines by hydrolysis with CsOH and LiAlH4 reduction, respectively.

Comparison of Electrophilic Amination Reagents for N‐Amination of 2‐Oxazolidinones and Application to Synthesis of Chiral Hydrazones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Iminomalonate as a Convenient Electrophilic Amination Reagent for Grignard Reagents.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Iminomalonate as a Convenient Electrophilic Amination Reagent for Grignard Reagents

Abstract Diethyl 2-[N-(p-methoxyphenyl)imino]malonate underwent amination reactions with alkyl Grignard reagents to give N-aklylation products in good yields. The obtained N-alkylation products were readily converted into N-alkyl-p-anisidines by the oxidative removal of the malonate moiety. The p-methoxyphenyl group was subsequently deprotected to give primary amines.

Electrophilic amination with iminomalonate

Diethyl N-anisyliminomalonate has been found to be an excellent electrophilic amination reagent for Grignard reagents to give N-alkylated products in good yields, and subsequent air oxidation affords N-alkylanisidines.

N-Boc-3-trichloromethyloxaziridine: a new, powerful reagent for electrophilic amination

The aza-Wittig reaction of Ph 3P=N-Boc with chloral, followed by the oxone oxidation of the resulting imine, afforded N-Boc-3-trichloromethyloxaziridine in excellent yield. This new oxaziridine proved to be a powerful electrophilic amination reagent.

ChemInform Abstract: N‐Alkyloxycarbonyl‐3‐aryloxaziridines: Their Preparation, Structure, and Utilization as Electrophilic Amination Reagents.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

N‐Alkyloxycarbonyl‐3‐aryloxaziridines: Their Preparation, Structure, and Utilization As Electrophilic Amination Reagents

AbstractThis paper reports the synthesis of a series of N‐protected oxaziridines (N‐Moc, Boc, Z or Fmoc) and discusses their ability to deliver their N‐alkoxycar‐bonyl fragment to amines, enolates, sulfur, and phosphorus nucleophiles (electrophilic amination). These oxaziridines are prepared by oxidation of the corresponding imines with oxone or anhydrous MCPBA lithium salt as the source of oxygen. They transfer their N‐protected fragment to primary and secondary amines to give protected hydrazines in fair to excellent yield. The nitrogen transfer to free amino acids (in form of their R4N+ salts) is particularly fast, even at low temperature, providing L (or D) N‐protected α‐hydrazino acids. Enolates are C‐aminated to give N‐protected α‐amino ketones, esters, or amides in modest yield, due to a side aldol reaction of the unreacted enolate with the released benzaldehyde. With tertiary amines (Et3N), sulfides (PhSMe), and phosphines (Ph3P), amination and oxidation proceed in a parallel way; the amount of amination product increases when the temperature is lowered (kinetic control). Some of the factors that can orient the oxaziridine reactivity towards amination or oxidation of nucleophiles are considered.

Synthesis of 3-Aminopyrocatechol via Lithiated Intermediates

We report the synthesis of 3-aminopyrocatechol (7) through electrophilic amination of lithiated pyrocatechol, protected in the form of a ketal. For this purpose the lithiation reaction of protected pyrocatechol (1) was studied. The synthesis of compounds (3) was achieved by the reaction of organolithium derivative (2) and a series of electrophilic reagents. Lithium-t-butyl-N-tosyloxycarbamate (5) was used as the electrophilic aminating reagent. With the cupro derivative (4) the protecting groups in compound (6) are removed in an acid medium by heating in ethanol-HCl solution (4:1).

A Novel Amination Reaction with Diphenyl Phosphorazidate: Synthesis of α‐amino‐acid derivatives

AbstractThe reaction of enolates of α‐unsubstituted carboxamides 3 with diphenyl phosphorazidate (DPPA) and di(tert‐butyl) dicarbonate (‘Boc anhydride’) in THF at −78° yielded 2‐{[(tert‐butoxy)carbonyl]amino}carboxamides 5 (Scheme 2) which are derivatives of α‐amino acids. In this reaction, DPPA acts as an electrophilic amination reagent. A reaction mechanism is proposed in Scheme 3.

ChemInform Abstract: Electrophilic Amination Reagents: A New Method for the Preparation of 3‐Aryl‐N‐BOC (or N‐FMOC) Oxaziridines.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Electrophilic amination reagents: A new method for the preparation of 3-Aryl-N-BOC (or N-FMOC) oxaziridines

N-BOC or N-FMOC benzaldimines are oxidized to the corresponding 3-Aryl-N-BOC or N-FMOC oxaziridines by reaction with Li m-chloroperoxybenzoate under aprotic conditions. The new oxaziridines can transfer their N-BOC or N-FMOC group to morpholine to give the corresponding N β-protected hydrazines.

Reaction of silyl enol ethers with arenediazonium salts. Part 2. α-Amination of esters

Diazonium salts efficiently serve as electrophilic aminating reagents of esters. The reaction of arenediazonium tetrafluoroborates with ketene silyl ketals yielded α-azo or α-hydrazono esters in good to excellent yields under very mild conditions. Hydrogenation of those esters gave α-amino esters quantitatively.

Electrophilic amination: first direct transfer of NHBoc with Li t-butyl-n-tosyloxycarbamate.

Lithium t-butyl-N-tosyloxycarbamate (LiBTOC) has been found to be an electrophilic aminating reagent. This species reacts with organometallic reagents, ester enolates and α-cuprophosphonates to provide primary amines as well as α-aminocarboxylic and phosphonic esters in their N-(Boc) protected form. (35–80 % isolated yields).