Applications Of α-oxo Ketenedithioacetals As Odorless Thiol Equivalent In Pesticide Synthesis

Dithioacetals, which are first synthesis from 1885, have proven to be useful in organic synthesis. Besides the use as thiol equivalents and an umpolung of the carbonyl group, the synthetic potential of dithioacetal functionality has been widely expanded in recent years.The former has provided effective method to avoiding thiols.Thiols have been extensively investigated as carbonyl protection groups and versatile intermediates in organic synthesis. Unfortunately, the conventional methods suffer from the use of volatile, foul-smelling, low molecular weight thiols that can lead to serious safety and environment problems. To resolve these drawbacks, some attempts have been made to develop odorless substitutes for these obnoxious thiols. As a result, a range of odorless or faint smell thiols have been prepared by increasing the alkyl chain length of thiol or introducing a trialkylsilyl group into the benzene ring of benzyl mercaptan and benzenethiol.Combining with the special properties ofα-oxo ketenedithioacetals, we have succeeded in exploring a new kind of reagents instead of thiols. Moreover,which have been successfully applied on protecting the carbonyl groups of aldehydes/ketones and Michael addition reaction in water and solvent-free conditions. This work mainly based on the following three aspects:1．Pyridaben have been synthesized through dithioacetals as a sulfur source, this method is associated with some synthetic advantages. The simple procedure, mild conditions, easy separation, high yields, and especially that in relation to the current environmental concerns, make this protocol most attractive for academic research and practical applications.2．Besides, We have synthesized successfully ethoprophos, this has demonstrated that dithioacetals is the various and practical reagent.In summary, we have succeeded in exploring a new kind of reagents instead of thiols, This method is associated with some synthetic advantages, such as simple procedure, fast reaction rate, high yields and mild conditions. So these new reagents have good perspective in the field of academic research and practical applications.