Process for performing an isolated Pd(II)-mediated oxidation reaction

Abstract

There is disclosed a process for performing an isolated Pd(II) mediated oxidation reaction electrochemically. The inventive process is performed on an electrode array device having a plurality of separately addressable electrodes. Preferably, the Pd(II) mediated oxidation is a Wacker reaction. Specifically, there is disclosed a process for conducting an isolated Pd(II) mediated oxidation on a plurality of electrodes, comprising providing an electrode array device having a plurality of electrodes with a conductive electrode surface and a matrix or coating material over the electrodes surfaces; providing a solution bathing the electrode array matrix or coating material and electrode surfaces, wherein the solution comprises a transition metal species and a confining agent; and biasing one or a plurality of electrodes (“selected electrode or electrodes”) with a voltage or current to regenerate the transition metal species required for the isolated Pd(II) mediated oxidation, whereby the confining agent limits diffusion of the transition metal species to a volume surrounding each selected electrode surface.

1 . A process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes, comprising: 
 (a) providing an electrode array device having a plurality of metallic or conductive electrodes each with a conductive surface, and having a matrix or coating material over the electrodes surfaces;    (b) providing a solution bathing the electrode array device, wherein the solution comprises a transition metal species and a confining agent; and    (c) biasing one or a plurality of electrodes (selected electrode or electrodes) on the electrode array device with a voltage or current to regenerate the transition metal species consumed during the Pd(II)-mediated reaction, whereby the confining agent limits diffusion of the transition metal species to a volume surrounding each selected electrode surface.    
     
     
         2 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 1  wherein the isolated Pd(II) mediated reaction is selected from the group consisting of a Wacker reaction, a Saegusa reaction, oxidative aryl coupling reactions, alkene to π-allyl palladium conversions, enol ether—organometallic coupling reactions, any other stoichiometric Pd(II) oxidation, and combinations thereof.  
     
     
         3 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 1  wherein the transition metal is a Pd (II) containing species.  
     
     
         4 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 3  wherein the transition metal is Pd(OAc) 2 .  
     
     
         5 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 1  wherein the Pd(II) species is regenerated by oxidation from Pd(0) by an intermediate oxident generated by a regeneration reaction at a selected electrode.  
     
     
         6 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 5  wherein the intermediate oxidant species is a triarylamine cation radical generated from a triaryl amine at the electrode.  
     
     
         7 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 1  wherein the confining agent is a reductant added to the solution sufficient to convert Pd(II) back to Pd(0) in areas not proximal to an activated electrode.  
     
     
         8 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 7  wherein the confining agent is a reductant selected from the group consisting of substituted or unsubstituted alkyl vinyl ethers, divinyl ether, aryl vinyl ether, alkene, H 2 , hydroquinones, and combinations thereof.  
     
     
         9 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 8  wherein the confining agent is a substituted or unsubstituted alkyl vinyl ether, wherein the alkyl moiety is a C 1-8  alkyl group.  
     
     
         10 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 1  wherein the biasing step uses a voltage no greater than 5V.  
     
     
         11 . The process for conducting an isolated Pd(II) mediated reaction on a plurality of electrodes of  claim 1  wherein the biasing step was performed for a time of from about 1 sec to about 10 min using a pulsed voltage or nonpulsed voltage.  
     
     
         12 . A process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix, comprising: 
 (a) providing an electrode array device having a plurality of metallic or conductive electrodes each with a conductive surface;    (b) providing a solution bathing the electrode array device, wherein the solution comprises a Pd(II) metal species and a confining agent;    (c) biasing one or a plurality of selected electrodes on the electrode array device with a voltage or current to perform a Wacker reaction regenerating the Pd(II) metal species consumed during the Wacker reaction and generating a free ketone or a free aldehyde moiety or a mixture of both, whereby the confining agent limits diffusion of the transition metal species to a volume surrounding each selected electrode surface; and    (d) providing a biological material having a free amino moiety to the electrode array device to selectively immobilize to the porous matrix located adjacent to the selected electrode(s).    
     
     
         13 . The process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix of  claim 12  wherein  
     
     
         14 . The process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix of  claim 12  wherein the Pd(II) species is regenerated by oxidation from Pd(0) by an intermediate oxident generated by a regeneration reaction at a selected electrode.  
     
     
         15 . The process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix of  claim 14  wherein the intermediate oxidant species is a triarylamine cation radical generated from a triaryl amine at the electrode.  
     
     
         16 . The process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix of  claim 12  wherein the confining agent is a reductant added to the solution sufficient to convert Pd(II) back to Pd(0) in areas not proximal to an activated electrode.  
     
     
         17 . The process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix of  claim 16  wherein the confining agent is a reductant selected from the group consisting of substituted or unsubstituted alkyl vinyl ethers, divinyl ether, aryl vinyl ether, alkene, H 2 , hydroquinones, and combinations thereof.  
     
     
         18 . The process for selectively immobilizing a biological molecule having a free amine moiety onto a selected region of a porous matrix of  claim 16  wherein the confining agent is a substituted or unsubstituted vinyl alkyl ether, wherein the alkyl moiety is a C 1-8  alkyl group.  
     
     
         19 . A process for conducting a parallel Wacker reaction on a plurality of electrodes, comprising: 
 (a) providing an electrode array device having a matrix or coating material over metallic or conductive electrodes surfaces and a plurality of electrodes;    (b) providing a solution bathing the electrode array device, wherein the solution comprises a transition metal species, solvent, and a confining agent; and    (c) biasing one or a plurality of electrodes on the electrode array device with a voltage or current to regenerate the transition metal species consumed during the Wacker reaction, whereby the confining agent limits diffusion of the transition metal species to a volume surrounding each selected electrode surface.    
     
     
         20 . The process for conducting a parallel Wacker reaction on a plurality of electrodes of  claim 19  wherein the transition metal reagent for the Wacker reaction is a palladium Pd(OAc) 2 .