Development of new selective alylation catalysis based on characteristic feature of water/organic solvent biphasic interface

研究了水/正己烷两相体系中含TPPTS配体的水溶性钯配合物催化苯乙烷烯丙基化反应。在该反应中，使用容易获得的烯丙醇作为烯丙基化试剂，并优先获得支链烯丙基硫醚。有趣的是，反应溶液的搅拌速度越高（1500 rpm），形成的支链烯丙基硫醚越多。这种通过机械搅拌的控制在一般化学反应中是非常罕见的。目前的选择性控制被认为是由高活性的η^1-烯丙基钯中间体的优先反应引起的，该中间体被认为是在水/己烷层的界面处产生的，通过苯乙撑的S_N2'反应，主要产生支链烯丙基硫化物。

The present research deals with water/hexane biphasic catalytic allylation of benzenethiol in the presence of water soluble palladium complex having TPPTS ligands. In this reaction, easily obtainable allylic alcohols were used as allylation reagents and branched allyllic sulfides were preferentially obtained. Interestingly, the more high stirring speed of the reaction solution(1500rpm), the more branched allylic sulfides formed. Such control by mechanistic stirring is very rare in chemical reactions in general. The present selectivity control is considered to be arisen from preferential reaction of highly activeη^1-allylpalladium intermediate which is considered to be produced in the interface of water/hexane layers, by S_N2' reaction of benzenethiol giving mainly branched allylic sulfides.