scholarly journals An anionic phosphenium complex as an ambident nucleophile

2015 ◽  
Vol 44 (13) ◽  
pp. 6023-6031 ◽  
Author(s):  
B. Stadelmann ◽  
J. Bender ◽  
D. Förster ◽  
W. Frey ◽  
M. Nieger ◽  
...  
Keyword(s):  
Ambident Nucleophile

Treatment of an N-heterocyclic chlorophosphine with Collman's reagent or K[HFe(CO)4]/NaH gave a unique anionic phosphenium complex which behaves as an ambident nucleophile.

Ambident reactivity in the reaction of phenoxide ion with 2-N-(2′,4′-dinitrophenyl)- and 2-N-(4′-nitrophenyl)-4,6-dinitrobenzotriazole 1-oxides, new superelectrophiles

1988 ◽  
Vol 66 (7) ◽  
pp. 1712-1719 ◽  
Author(s):  
Erwin Buncel ◽  
Julian M. Dust
Keyword(s):  
Activation Energy ◽  
Adduct Formation ◽  
Reaction Pathways ◽  
Resonance Spectroscopy ◽  
The Novel ◽  
Reaction Series ◽  
Bond Scission ◽  
Energy Reaction ◽  
Successive Removal ◽  
Ambident Nucleophile

Reaction of the novel superelectrophiles 2-N-(2′,4′-dinitrophenyl)- and 2-N-(4′-nitrophenyl)-4,6-dinitrobenzotriazole 1-oxides, 3, and 4, possessing two electrophilic centres, with the ambident nucleophile potassium phenoxide in (CD3)2SO was followed by 400 MHz 1H nuclear magnetic resonance spectroscopy. A dichotomy in the reaction pathways has been observed. With MeO−, attack at C-7 leads to reversible adduct formation, while attack at C-1′ results in irreversible N-2: C-1′ bond scission via the metastable C-1′ adduct. In contrast, the reaction of 3 and 4 with PhO− proceeds by a two-pronged attack: formation of C-7 carbon-bonded phenoxide adducts via the ortho and para carbon sites, and oxygen-based cleavage products by attack at the C-1′ position, accompanied by N-2:C-1′ bond scission, in accord with the ambident reactivity of PhO−. Significantly, in this case reaction of both C-7 and C-1′ is effectively irreversible. Moreover, the reaction of phenoxide with either 3 or 4 shows striking differences compared to the reaction of PhO− with 2-N-(picryl)-4,6-dinitrobenzotriazole 1-oxide, 1. Reaction of PhO− with 1 resulted only in O-attack at C-1′ and N-2:C-1′ bond scission; there was no evidence for C-7 adduct formation via O- or C-attack. This marked difference in behaviour can be attributed to the decreased susceptibility to C-1′ attack exhibited by 3 and 4 as compared to 1 and arises from the successive removal of electron-withdrawing nitro groups from the 2-N′-nitroaryl moiety in the series 1 → 3 → 4. The reactions are discussed on the basis of selectivity considerations and an activation energy/reaction coordinate profile comparing the pathways for both C-attack at C-7 and O-attack at C-l′ as electrophilicity (delocalizability) is progressively modulated in the reaction series.

ChemInform Abstract: GEM-DICHLORALLYLLITHIUM, A SEEMINGLY AMBIDENT NUCLEOPHILE

1974 ◽  
Vol 5 (20) ◽  
pp. no-no
Author(s):  
D. SEYFERTH ◽  
G. J. MURPHY ◽  
R. A. WOODRUFF
Keyword(s):  
Ambident Nucleophile

ChemInform Abstract: Regiocontrolled Iodoaminocyclization Reaction of an Ambident Nucleophile Mediated by Basic Metallic Reagent.

ChemInform ◽  
2010 ◽  
Vol 29 (11) ◽  
pp. no-no
Author(s):  
M. FUJITA ◽  
O. KITAGAWA ◽  
T. SUZUKI ◽  
T. TAGUCHI
Keyword(s):  
Ambident Nucleophile

Photoredox catalyzed cascade CF3 addition/chemodivergent annulations of ortho-alkenyl aryl ureas

2022 ◽  
Author(s):  
Sakamuri Sarath Babu ◽  
A Anagha Varma ◽  
Purushothaman Gopinath
Keyword(s):  
Photoredox Catalysis ◽  
Cascade Cyclization ◽  
Ambident Nucleophile

Herein, we report a substrate-controlled cascade cyclization of o-alkenyl aryl ureas, an ambident nucleophile for constructing functionalized heterocycles such as 2-amino-1,3-benzoxazines and dihydroquinazolinones in a chemodivergent fashion using photoredox catalysis...

gem-chloro(trimethylsilyl)allyllithium: A novel ambident nucleophile

1978 ◽  
Vol 156 (2) ◽  
pp. 279-297 ◽  
Author(s):  
Dietmar Seyferth ◽  
Robert E. Mammarella
Keyword(s):  
Ambident Nucleophile

The 1,3,5-Trinitrobenzene–Phenoxide σ-Complex. Ambident Phenoxide Ion in SNAr Systems

1975 ◽  
Vol 53 (24) ◽  
pp. 3761-3767 ◽  
Author(s):  
Erwin Buncel ◽  
Andrzej Jończyk ◽  
John G. K. Webb
Keyword(s):  
Dimethyl Sulfoxide ◽  
Product Formation ◽  
Mineral Acid ◽  
Thermodynamic Control ◽  
Aromatic Carbon ◽  
Dimethyl Sulfoxide Solution ◽  
A Minor ◽  
Ambident Nucleophile

1,3,5-Trinitrobenzene reacts with potassium phenoxide in dimethyl sulfoxide solution to yield a σ-complex in which bonding has occurred between the para carbon of the phenoxy moiety and an unsubstituted carbon of the nitroaromatic substrate. A minor proportion of ortho adduct is also obtained. When the reaction is performed in DMSO–MeOH (80:20, v/v) one obtains initially the methoxide adduct of TNB which is then smoothly transformed into the phenoxide adduct. The latter is stable to dilute mineral acid, unlike the former; formation of a σ-complex involving bonding between the phenoxy oxygen and a carbon of TNB is thereby excluded. The reaction represents the first instance of phenoxide ion acting as an ambident nucleophile towards aromatic carbon. The implication of this finding on the course of related SNAr reactions is discussed on the basis of kinetic and thermodynamic control of product formation.

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