Concept

Leaving group

Publications associées (58)

Wittig rearrangement of lithiated allyl aryl ethers: a mechanistic study

A -75 DegC, alpha-lithiated allyl Ph ether undergoes mainly the Wittig rearrangement to afford, after acidic hydrolysis, 1-phenyl-2-propen-1-ol as the main product. A second metalation taking place at one of the ortho positions is the sole competing side r ...

2006

Electron transfer induced dissociation of chloro-cyano-benzene radical anion: driving chemical reactions via charge restraints

Ursula Röthlisberger

We introduce a new quantum mechanics/mol. mechanics based method to drive electron transfer reactions. Our approach uses the dynamically restrained electrostatic potential derived charges of the quantum atoms as a reaction coordinate, and allows an estn. o ...

2005

The reactivity of 2-fluoro- and 2-chloropyridines toward sodium ethoxide: Factors governing the rates of nucleophilic (het)aromatic substitutions

Thierry Rausis

The relative displacement rates of the halide substituent from 2-fluoro- and 2-chloropyridines by EtONa in EtOH at +25 Deg were assessed by competition kinetics. The 2-fluoropyridine reacts 320 times faster than the chloro analog. A CF3 group increases the ...

2005

Palladium-catalyzed desulfitative Mizoroki-Heck couplings of sulfonyl chlorides with mono- and disubstituted olefins: Rhodium-catalyzed desulfitative heck-type reactions under phosphine- and base-free conditions

Pierre Vogel

New conditions have been found for the desulfitative Mizoroki-Heck arylation and trifluoromethylation of mono- and disubustituted olefins with arenesulfonyl and trifluoromethanesulfonyl chlorides. Thus (E)1,2-disubstituted alkenes with high stereoselectivi ...

2005

Oxidation of CS2 by AsBr4+: The unexpected formation of the simple CS2Br3+ carbenium ion

During the prepn. of AsBr4+[Al(OR)4]-, the novel carbocation CS2Br3+ was synthesized by reaction of AsBr3, Br2, CS2, and Ag[Al(OR)4] (R=C(CF3)3). CS2Br3+ [Al(OR)4]- was characterized by its crystal structure, NMR and IR spectroscopy, and quantum chem. calc ...

2004

DRIFTS and transient-response study of vanadia/titania catalysts during toluene partial oxidation

Albert Renken, Lioubov Kiwi, Fabio Rainone

The role was studied, of bulk V2O5 in vanadia/titania catalysts in partial oxidn. of toluene. Two catalysts with 1.8 and 11.1% of V were studied, by in situ DRIFTS and transient-response methods. Bulk V2O5 was found by FT-Raman spectroscopy only in the 11. ...

2003

From central to planar chirality, the first example of atropenantioselective cycloetherification

Jieping Zhu

Using chiral quaternary ammonium hydroxide as base, cycloetherification of a linear achiral diarylheptanoid compd., by way of an intramol. SNAr reaction, provides corresponding enantiomerically enriched cyclophane in good to excellent yield. [on SciFinder ...

2003

A Convergent Approach to Cyclopeptide Alkaloids: Total Synthesis of Sanjoinine G1

Jieping Zhu

A general strategy for the synthesis of cyclopeptide alkaloids contg. an endocyclic aryl-alkyl ether bond has been developed featuring a key intramol. SNAr reaction. The importance of the N-terminal protective group in the realization of such a strategy is ...

2002

PX4+, P2X5+, and P5X2+ (X = Br, I) salts of the superweak Al(OR)4- anion [R = C(CF3)3]

Ines Raabe, Lutz Müller

PX4+[Al(OR)4]- (X = I: 1a, X = Br: 1b) was prepd. from X2, PX3, and Ag[Al(OR)4] [R = C(CF3)3] in CH2Cl2 at -30 Deg in 69-86% yield. P2X5+ salts were prepd. from 2PX3 and Ag[Al(OR)4] in CH2Cl2 at -30 Deg yielding almost quant. P2X5+[Al(OR)4]- (X = I: 3a, X ...

2002

A Rapid Access to Biaryl Ether Containing Macrocycles by Pairwise Use of Ugi 4CR and Intramolecular SNAr-Based Cycloetherification

Jieping Zhu

An Ugi reaction promoted by ammonium chloride in aprotic solvent is documented here for the first time. From readily accessible starting materials, macrocycles with an endo aryl-aryl ether bond are synthesized in only two steps, Ugi four-component reaction ...

2001

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