Hiroaki Murase

Electroreductive synthesis of oligosilanes and polysilanes with ordered sequences

Abstract The stepwise elongation of SiSi or SiGe chain was achieved by the electroreductive cross-coupling reaction of chlorohydrosilanes with dichlorooligosilanes using magnesium electrodes. The electroreductive cross-coupling reaction of chlorodimethylsilane ( 1 ) with dichlorodiphenylsilane ( 2 ) or dichlorodiphenylgermane ( 4 ), for instance, gave 1,3-dihydro-1,1,3,3-tetramethyl-2,2-diphenyltrisilane ( 3 ) or bis(hydrodimethylsilyl)germane ( 5 ) in good yield. Compounds 3 and 5 were readily transformed to the corresponding 1,3-dichlorotrisilane ( 6 ) and bis(chlorosilyl)germane ( 7 ), respectively. The electroreductive polymerization of the resulting dichlorooligosilanes using magnesium electrodes in tetrahydrofuran was successfully applied to the synthesis of sequence-ordered polysilanes.

Electroreduction of aliphatic esters using new paired electrolysis systems

Electroreduction of aliphatic esters to form 2-alkoxytetrahydrofurans was achieved by using a new paired electrolysis system, that consists of the cathodic reduction of aliphatic esters and the anodic oxidation of the solvent (THF). It was also found that the presence of magnesium ion in the electrolyte promoted the electroreduction of aliphatic esters remarkably. In fact, the electroreduction of aliphatic esters was found to proceed toward 2-alkoxytetrahydrofurans by using a platinum cathode and anode in the presence of anodically dissolved magnesium ions.

Electroreduction of aromatics using magnesium electrodes in aprotic solvents containing alcoholic proton donors

Abstract Regioselective electroreduction of the aromatics, including methoxybenzenes, by using LiClO4 as a supporting electrolyte in an aprotic solvent (THF) containing alcoholic proton donors such as t-BuOH was successfully achieved to afford the corresponding 1,4-cyclohexadienes regioselectively in high yield. The electrolysis can be performed under constant current conditions at ambient temperature. The effect of electrode materials was remarkable, that is, the use of Mg electrodes gave the best result. Moreover in the presence of t-BuOD instead of t-BuOH, the deutrated 1,4-cyclohexadienes were obtained in high deuterium incorporation at 1- and 4-positions. A direct electron transfer to the aromatics is unlikely, and it is reasonable that the solvated Li(0), which is generated by the cathodic reduction of LiClO4, is intermediately involved in the electron transfer with being assisted by the anodically generated Mg2+ as an electron transfer catalyst.