Research In Silver(Ⅰ)-mediated Reaction Of Alkynes&Alkynyl Silanes With Sulfonyl Chlorides And Synthesis Of γ-substitutedα-Diazo-β-keto Ester Derivatives

The reactions of alkynes or alkynyl silanes with sulfonyl chlorides in the presence of silver salts have mainly been exploited in this paper. And the corresponding reaction mechanisms have been proposed. In addition, functionalized α-diazo-β-keto ester has been studied. This thesis consists of four parts.1. These methods for preparation of α, β-unsaturated sulfones and application in organic synthesis have been reviewed.2. The reaction of alkyne with sulfonyl chloride in the presence of different silver salts has been explored, and this optimal reaction conditions are concluded as below: molar ratio of alkynes and sulfonyl chloride2:1, use of10mol%silver fluoride or silver nitrate as catalyst in THF at room temperature under nitrogen, α, β-Unsaturated sulfone (yield of48%-79%) and β-keto sulfone (yield of20%-28%) can be yielded when terminal aromatic alkynes were used as substrates. However, the reaction cannot occur when unterminal alkynes and terminated aliphatic alkynes were employed as substrates. A reasonable reaction mechanism has been proposed based on our experimental results.3. The reaction of alkynyl silane with sulfonyl chloride in the presence of various silver salts has been exploited, and this optimal reaction conditions are as below: molar ratio of alkynyl silane and sulfonyl chloride2:1, use of1.1eq silver nitrate in THF at room temperature under nitrogen, α, β-Unsaturated sulfone (in51%-61%yield) and β-keto sulfone (in17%-28%yield) can be obtained when aromatic alkynyl silanes were used as substrates. However, utilization of alkyl acetylenic silanes as substrates did not afford any products. A reasonable reaction mechanism has been suggested.4. The y-functional ization of α-diazo-β-keto ester was preliminarily studied. The y-phenylselenyl and y-iodo α-diazo-β-keto ester were synthesized by reactions of the α-diazo-β-keto ester and phenylselenyl bromide or iodine in the presence of Lewis acid and weak base in CH2Cl2at-15℃under nitrogen.All new compounds were determined by IR, H NMR,13C NMR and MS.