ChemInform Abstract: 1,2-Disubstituted [(η6-Arene)Cr(CO)3] Complexes by Sequential Nucleophilic Addition/endo-Hydride Abstraction.

ChemInform ◽  
2010 ◽  
Vol 29 (23) ◽  
pp. no-no
Author(s):  
A. FRETZEN ◽  
A. RIPA ◽  
R. LIU ◽  
G. BERNARDINELLI ◽  
E. P. KUENDIG
Keyword(s):  
Nucleophilic Addition ◽  
Hydride Abstraction

1,2-Disubstituted [(η6-Arene)Cr(CO)3] Complexes by Sequential Nucleophilic Addition/endo-Hydride Abstraction

1998 ◽  
Vol 4 (2) ◽  
pp. 251-259 ◽  
Author(s):  
Angelika Fretzen ◽  
Alberto Ripa ◽  
Ronggang Liu ◽  
Gerald Bernardinelli ◽  
E. Peter Kündig
Keyword(s):  
Nucleophilic Addition ◽  
Hydride Abstraction

Natural Product Synthesis by C–H Functionalization: (–)-Zampanolide (Ghosh), Muraymycin D2 (Ichikawa), (+)-Sundiversifolide (Iwabuchi), (+)-Przewalskin B (Zhang/Tu), Artemisinin (Wu)

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Absolute Configuration ◽  
Nucleophilic Addition ◽  
Active Component ◽  
Oxidative Cyclization ◽  
Natural Product Synthesis ◽  
Protecting Groups ◽  
Keto Ester ◽  
Du Bois ◽  
Ether Oxygen ◽  
Hydride Abstraction

Arun K. Ghosh of Purdue University exposed (Org. Lett. 2011, 13, 4108) the ether 1 to DDQ. Hydride abstraction initiated nucleophilic addition of the allyl silane, which proceeded with high diastereocontrol to deliver 2, a key intermediate in the synthesis of (+)-zampanolide 3. Satoshi Ichikawa, after surveying (Org. Lett. 2011, 13, 4028) several N-protecting groups, settled on the phthalimide 4 as the best for directing the Du Bois oxidative cyclization. The sulfamate 5 was carried forward to a key component for the assembly of muraymycin D2 6. Yoshiharu Iwabuchi of Tohoku University found (Org. Lett. 2011, 13, 3620) that the silyl diazo ester 7 cyclized with high regiocontrol, inserting with retention of absolute configuration into the H adjacent to the ether oxygen. The insertion also proceeded with high diastereocontrol, to deliver an intermediate silyl lactone that was suitably arrayed for the subsequent Peterson elimination to give 8, a key intermediate for the synthesis of (+)-sundiversifolide 9. Fu-Ming Zhang and Yong-Qiang Tu of Lanzhou University prepared (J. Org. Chem. 2011, 76, 6918) the α-diazo β-keto ester 10. Rh-catalyzed intramolecular C–H insertion, again with retention of absolute configuration, gave an intermediate that on deprotection cyclized to the lactone 11, only a few steps removed from (+)-przewalskin B 12. Yikang Wu of the Shanghai Institute of Organic Chemistry devised (Org. Lett. 2011, 13, 4212) a novel preparation for cyclic peroxides such as 13. Gentle oxidation of 13 led to 14, which was further oxidized to artemisinin 15. Also known as qinghaosu, 15 is the key active component of current antimalarials.

Metallorganische Lewissäuren, V [1] Reaktionen von Carbonyl-η5-cyclopentadienylmolybdä ntetrafluoroboraten (η5-C5H5)MO(CO)2(L)FBF3 (L=CO, PR3) mit Phosphanen und Alkenen / Organometallic Lewis Acids, V [1] Reactions of Carbonyl-η5-cyclopentadienyl Molybdenum Tetrafluoroborates (η5-C5H5)Mo(CO)2(L)FBF3 (L = CO, PR3) with Phosphanes and Alkenes

1981 ◽  
Vol 36 (4) ◽  
pp. 474-481 ◽  
Author(s):  
Karlheinz Sünkel ◽  
Herbert Ernst ◽  
Wolfgang Beck
Keyword(s):  
Nucleophilic Addition ◽  
Lewis Acids ◽  
Chelate Compound ◽  
Trans Butene ◽  
Hydride Abstraction ◽  
Cis And Trans

AbstractTetrafluoroborate complexes (η5 -C5H5)Mo(CO)2(PR3)FBF3 have been prepared by hydride abstraction from the corresponding hydrido compounds using Ph3CBF4. The tetrafluoroborate ligand in (η5 -C5H5)Mo(CO)2(L)FBF3 (L = CO, PR3) is easily sub-stituted by phosphanes, cis-and trans-butene(2), a-acetamidocinnamic acid and buta-diene. Nucleophilic addition of HNMe2 to the butadiene complex [(η5 -C5H5)Mo(CO)3 butadiene)]+BF4- gives the β-aminoacyl chelate compound 7.

Synthesis, Structure and Reactivities of Pentacoordinated Phosphorus–Boron Bonded Compounds

2020 ◽  
Author(s):  
Nathan O'Brien ◽  
Naokazu Kano ◽  
Nizam Havare ◽  
Ryohei Uematsu ◽  
Romain Ramozzi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Bicyclic Compound ◽  
Compound A ◽  
Ligand System ◽  
Large Bulk ◽  
Rearrangement Reaction ◽  
Hydride Abstraction ◽  
Pentacoordinated Phosphorus ◽  
Acids And Bases

<div>The isolation and reactivities of two pentacoordinated phosphorus–tetracoordinated boron bonded compounds were</div><div>explored. A strong Lewis acidic boron reagent and electron-withdrawing ligand system were required to form the</div><div>pentacoordinated phosphorus state of the P–B bond. The first compound, a phosphoranyl-trihydroborate, gave a THF</div><div>stabilised phosphoranyl-borane intermediate upon a single hydride abstraction in THF. This compound could undergo a</div><div>unique rearrangement reaction, that involved a two-fold ring expansion, to give an unusual fused bicyclic compound or it</div><div>could act as a mono-hydroboration reagent. The hydroboration reactivity of the intermediate was found to be more reactive</div><div>towards alkynes over alkenes with good to moderate regioselectivity towards the terminal carbon. The second compound,</div><div>a phosphoranyl-triarylborate, was found to have a vastly different reactivity to the trihydroborate as it was highly stable</div><div>towards acids and bases. This is thought to be due to the large bulk around the P–B bond as shown in the crystal structure</div>

Recent Progress in Chemosensors Using Aldehyde-bearing Fluorophores for the Detection of Specific Analytes and their Bioimaging

2019 ◽  
Vol 26 (21) ◽  
pp. 4003-4028 ◽  
Author(s):  
Fangjun Huo ◽  
Yaqiong Zhang ◽  
Caixia Yin
Keyword(s):  
Biomedical Research ◽  
Nucleophilic Addition ◽  
Recent Progress ◽  
Biological Imaging ◽  
Tissue Imaging ◽  
Fluorescence Probes ◽  
Biological Applications ◽  
Convenient Procedure ◽  
Nucleophilic Mechanism

In recent years, aldehyde-appended fluorescence probes have attracted increasing attention. Fluorescent biological imaging includes many modern applications for cell and tissue imaging in biomedical research. Meanwhile, the nucleophilic mechanism is a very simple and convenient procedure for the preparation of aldehyde-sensing probes. This tutorial review focuses on aldehyde-bearing chemosensors based on nucleophilic addition mechanism with biological applications.

Formation of spiro adduct from N-methyl-N-(2,4,6-trinitrophenyl)glycine anion

1989 ◽  
Vol 54 (2) ◽  
pp. 440-445 ◽  
Author(s):  
Vladimír Macháček ◽  
Alexandr Čegan ◽  
Miloš Sedlák ◽  
Vojeslav Štěrba
Keyword(s):  
Nmr Spectroscopy ◽  
Dimethyl Sulfoxide ◽  
Equilibrium Constant ◽  
Mole Fraction ◽  
Nucleophilic Addition ◽  
Adduct Formation ◽  
First Case ◽  
C Nmr

The intramolecular nucleophilic addition of N-methyl-N-(2,4,6-trinitrophenyl)glycine anion in methanol-dimethyl sulfoxide mixtures produces spiro[(3-methyl-5-oxazolidinone)-2,1'-(2',4',6'-trinitrobenzenide)]. The spiro adduct has been identified by means of 1H and 13C NMR spectroscopy. This is the first case when the formation of a Meisenheimer adduct with carboxylate ion is observed. Logarithm of the equilibrium constant of adduct formation increases linearly with the mole fraction of dimethyl sulfoxide in its mixture with methanol.

Regioselective Functionalization of N-Fused Heteroaromatics via FeCl3-Catalyzed Nucleophilic Addition to Activated N-Heterocycles

Synthesis ◽  
2020 ◽  
Author(s):  
Ikyon Kim ◽  
Sung June Kim ◽  
Sunhee Lee
Keyword(s):  
Aromatic Compounds ◽  
Nucleophilic Addition ◽  
Chemical Space ◽  
Wide Range ◽  
Regioselective Functionalization

AbstractBroadening of nitrogen-fused heteroaromatic chemical space such as indolizine and pyrrolo[1,2-a]pyrazine was achieved via FeCl­3-catalyzed nucleophilic addition of these N-fused aromatic compounds to a wide range of azolinium systems generated in situ, leading to novel N-fused heteroaromatic scaffolds with dearomatized N-heterocyclic substituents regioselectively. Nucleophilic addition of indolizines and pyrrolo[1,2-a]pyrazines mainly occurred at the C1 position of the isoquinoliniums and at the C4 site of the quinoliniums.

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