One-pot Synthesis Of Methylthio Aryl Alkynes And Researches On The Mechanism

It was reported that organic compounds containing thiomethyls at the terminal can assemble gold nanoparticle to gold nanoparticle cluster. The shape and size of the cluster can be adjusted.πconjugate aryl alkynyl thio ethers containing thiomethyl in the end are important compounds. We can use such compounds to get some functional molecules that have good assemblied effect, especially in controlling the shape and the size of the cluster. Therefore, designing and synthesizingπconjugate compounds have prime theoretical and practical value.In order to get the aryl alkynyl thio ether, we need to synthesize some important terminal functional compounds. Based on the preceding reaearch of our laboratory, we selected methyl thio methyl phenyl sulfone (MP-S) as nucleophilic reagent to eract with aromatic aldehyde and synthesized successfully a series of methylthio aryl ethynes I_a-h by"one-pot"reaction .The target compounds I_a-h provide possibility to construct different aryl alkynyl thio ethers.MP-S is widely used an an orgaic sulfur reagent, but the utilization is limited for its low yield. According to the literature, we made some improvements in the method. The new method shortened react time and raised the yield of MP-S from 38% to 51.2%.Next, we tried to synthesize methyl thio aryl akkynes by"one-pot"reaction. After analyzing the structure of MP-S, we knew it had an active methylene, when the methylene took part in neclophilic addition reaction, a new elimination reaction would begin, in which benzensulfonyl and methythio connected with the methylene would be good leaving groups. So, we used MP-S as nucleophilic reagent. First we treated MP-S with strong base, second added reaction nass and then got the target compounds I_a-h in good yield with"one-pot".In the end, we had a systematic study on the"one-pot"reaction mechanism. According to the products, we inferred it was a double elimination reaction. MP-S firsrt turned to carbanion in the existion of strong base. Then the carbanion of MP-S reacter with aryl aldehyde, diethyl chlorophosphate and the intermediate compounds V was synthesized. The compound V underwent two eliminations to attain the target compounds I_a-h. On testing compound V, diethyl chlorophosphate was displaced with water or acetyl chloride, intermediate compounds VI and VII were isolated. Compounds II_a-h were also good evidence to support this double...