Publications de Fabrice Cottet

Publications associées (9)

The gas phase acidity of oligofluorobenzenes and oligochlorobenzenes: about the additivity or non-additivity of substituent effects

The deprotonation energies of benzene, fluorobenzene, all di-, tri-, and tetrafluorobenzenes, pentafluorobenzene, chlorobenzene, all di-, tri-, and tetrachlorobenzenes, and pentachlorobenzene have been calcd. at various levels of second-order Moller-Plesse ...

2005

Metalation and derivatization of all six dichlorobenzotrifluorides: Site selectivities

Fabrice Cottet, Carla Bobbio, Eric Masson

The metalation of 2,3-, 2,6-, 2,4- and 3,5-dichlorobenzotrifluorides can be readily effected with std. reagents such as lithium diisopropylamide, lithium 2,2,6,6-tetramethylpiperidide, and butyllithium at the chlorine-adjacent 4- and 3-positions and the ch ...

2005

The metalation of 1- and 2-(trifluoromethyl)naphthalenes: Noteworthy site selectivities

Fabrice Cottet

This article provides insight into the various factors by which electroneg. substituents affect the kinetic acidity of arenes and, more specifically, naphthalenes. Both 1- and 2-(trifluoromethyl)naphthalenes were consecutively treated with an organometalli ...

Georg Thieme Verlag2005

Heterosubstituted or functionalized derivatives of 1- and 2-(trifluoromethyl)naphthalenes emanating from aryne adducts

Fabrice Cottet, Frédéric Bailly

More than two dozen new CF3-substituted naphthalene derivs. were prepd. in an expedient way by employing 3- and 4-(trifluoromethyl)benzyne as the key intermediates. 2- And 4-Chlorobenzotrifluoride were treated with butyllithium and the organometallic speci ...

Georg Thieme Verlag2005

A large-scale low-cost access to the lithium 2,2,6,6-tetramethylpiperidide precursor

Fabrice Cottet

Wolff-Kishner-Huang redn. of the cheap 2,2,6,6-tetramethyl-4-piperidinone provides the expensive 2,2,6,6-tetramethylpiperidine, the precursor to lithium 2,2,6,6-tetramethylpiperidide, in high yield. As specified in the detailed protocol, the reaction can b ...

Georg Thieme Verlag2005

Relay propagation of crowding: the trifluoromethyl group as both an emitter and transmitter of steric pressure

Rosario Scopelliti, Fabrice Cottet, Christophe Heiss, Eric Masson

Whereas lithium 2,2,6,6-tetramethylpiperidide (LITMP) abstrs. a proton exclusively from the 4-position of 3-bromobenzotrifluoride, the same base attacks selectively the 2-position when employed in the presence of N,N,N',N'',N''-pentamethyldiethylenetriamin ...

2006

Meta- rather than ortho-directed metalations: Buttressing effects prejudicing the proton abstraction from (2,6-dihalophenyl)silanes

Fabrice Cottet, Christophe Heiss

(2,6-Dichlorophenyl)trimethyl- and -triethylsilane exhibit untypical reactivity patterns toward strong bases. When treated at -100 DegC with lithium 2,2,6,6-tetramethylpiperidide, they give rise to two, with sec- or tert-butyllithium even three, different ...

2005

Converting core compounds into building blocks: The concept of regiochemically exhaustive functionalization

Fabrice Cottet, Carla Bobbio

In a model study, 3-fluorophenol and 3-fluoropyridine were converted into all possible regioisomers of the corresponding carboxylic acids by passing through the corresponding organometallic intermediates. As an attempt to generalize the findings reveals, a ...

2005

Fluorine in an heterocyclic context : preparation and functionalization of trifluoromethylpyridines

Fabrice Cottet

EPFL2003