Jean Santamaria

Photo-oxygenations de composes aromatiques sensibilisees par des accepteurs d'electron

Abstract Photo-oxygenation of aromatic compounds sensitized by electron acceptors, like 9-10 dicyanoanthracene (DCA) is shown to proceed by two distinct mechanisms each one beginning by an electron-transfer step: in the first way superoxide ion [O 2 − ] is involved and in the second one singlet oxygen [ 1 O 2 * ] is produced according to an unusual process.

Singlet oxygen mediated alkaloid tertiary amines oxidation by single electron transfer

Abstract A chemical study of the oxidation of tertiary amines and alkaloids through monoelectronic transfer is presented and allows us to assign to singlet oxygen a new behavior as electron acceptor during the oxidation process.

Trimethylsilyl cyanide as a superior trapping agent for iminium ion intermediates in the dca-sensitized photooxygenation of indole derivatives and analogues. Application to the total synthesis of some indoloquinolizidine alkaloids

Abstract A photoinduced electron transfer process sensitized by 9,10-dicyanoanthracene (DCA), using Me 3 SiCN (TMSCN) an cyanating agent, yields α-aminonitriles in the indole derivatives and analogues series. Efficient synthesis of indoloquinolizidine alkaloids through a Pictet-Spengler cyclization applied to these α-aminonitriles generated in situ is described.

Electron-transfer activation. Photochemical N-demethylation of tertiary amines

Abstract DAP2+ sensitized photooxidation of some biologically active N-methylated alkaloids affords the corresponding secondary amines in excellent yields (80-95 %).

Electron-transfer activation. Salt effects on the photooxidation of tertiary amines : A useful N-demethylation method

Abstract Photooxidation of tertiary methylamines sensitized by electron acceptors like 9,10-dicyanoanthracene is shown to proceed by two distinct ways depending on the presence of added salts. In the absence of added salt both nor and N-formyl compounds were obtained while with added salt the nor-derivative is obtained highly efficiently.

Electron Transfer Activation - A Selective Photooxidation Method for the Preparation of Aromatic Aldehydes and Ketones

Abstract A selective and mild photocatalytic procedure for benzylic oxydations with 9,10-dicyanoanthracene (DCA), an usual electron acceptor, in presence of methyl viologen (MV 2+ ) and FeCl 2 has been developed.

Regioselective single electron transfer photocatalytic synthesis of 2-cyano-3-ethylidenepiperidines. New route to the total synthesis of (±) cis-eburnamonine

Abstract A new synthesis of (±) cis- eburnamonine is described through a tetracyclic key intermediate 3 obtained from 2-cyano-3-ethylidenepiperidines generated in situ by a regioselective single electron transfer (SET) photocatalysis.

Electron transfer activation. Hydroperoxide intermediates in a novel and selective procedure for benzylic oxidations

Abstract A selective and mild photochemical procedure for benzylic oxidations with 9,10-dicyanoanthracene (DCA), an usual electron acceptor, in the presence of methyl viologen (MV 2+ ), an electron relay, has been developed. Methyl and methylene groups are oxidized in good to excellent yields to the corresponding hydroperoxides.