高等学校化学学报
高等學校化學學報
고등학교화학학보
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES
2014年
2期
286-291
,共6页
催化内酯化反应%有机高价碘中间体%碘化铵%4-戊烯酸
催化內酯化反應%有機高價碘中間體%碘化銨%4-戊烯痠
최화내지화반응%유궤고개전중간체%전화안%4-무희산
Catalytic halolactonization%Hypervalent iodine intermediate%Ammonium iodide%4-Pentenoic acid
研究了不饱和烯酸在碘化铵催化作用下的溴代和氯代内酯化反应。通过该反应,4-戊烯酸等不饱和烯酸在催化剂碘化铵和氧化剂间氯过氧苯甲酸作用下很容易与溴化锂和氯化锂反应,常温下短时间内即可得到良好产率的溴/氯甲基γ-丁内酯化合物,从而建立了一个简单快速合成溴/氯甲基γ-丁内酯的新方法。考察了反应条件对反应的影响,提出了该反应是经过有机高价碘中间体而进行的反应机理。
研究瞭不飽和烯痠在碘化銨催化作用下的溴代和氯代內酯化反應。通過該反應,4-戊烯痠等不飽和烯痠在催化劑碘化銨和氧化劑間氯過氧苯甲痠作用下很容易與溴化鋰和氯化鋰反應,常溫下短時間內即可得到良好產率的溴/氯甲基γ-丁內酯化閤物,從而建立瞭一箇簡單快速閤成溴/氯甲基γ-丁內酯的新方法。攷察瞭反應條件對反應的影響,提齣瞭該反應是經過有機高價碘中間體而進行的反應機理。
연구료불포화희산재전화안최화작용하적추대화록대내지화반응。통과해반응,4-무희산등불포화희산재최화제전화안화양화제간록과양분갑산작용하흔용역여추화리화록화리반응,상온하단시간내즉가득도량호산솔적추/록갑기γ-정내지화합물,종이건립료일개간단쾌속합성추/록갑기γ-정내지적신방법。고찰료반응조건대반응적영향,제출료해반응시경과유궤고개전중간체이진행적반응궤리。
A novel halolactonization of pentenoic acids was developed, which was catalyzed by hypervalent io-dine species generated in situ from ammonium iodide. In this protocol, 4-pentenoic acids reacted easily with lithium bromide or lithium chloride under catalyst ammonium iodide in combination with m-chloroperbenzoic acid( mCPBA) as the terminal oxidant in CH3 CN at room temperature, which provided five-membered halolac-tones in moderate to good yields. A new plausible reaction pathway for the reaction was hypothesized. Thus, NH4 I was first oxidized to I2 and HOI with mCPBA, both of them reacted with alkenoic acid to form the iodola-ctone, which then was transformed into the hypervalent iodine intermediate in situ by the continuing oxidation, and finally the halolactone was provided when lithium bromide or lithium chloride was acted as nucleophile in the following intermolecular nucleophilic substitution. This method has some advantages such as mild reaction conditions, simple procedure and good yields. Furthermore, the scope of hypervalent iodine reagents in organic synthesis could be extended.