磷催化的脱氧缩合的理论研究
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- 英文论文题名：The mechanism of phosphetane-catalyzed Deoxygenative condensation:P(Ⅲ)/P(V)=O Redox Cycling
- 论文作者：杨冬月 ; 方德彩
- 英文论文作者：Dong-Yue Yang ; De-Cai Fang ; Department of Chemistry ; Beijing Normal University
- 年：2016
- 作者机构：北京师范大学化学学院;
- 论文关键词：磷催化 ; 氧化还原 ; 脱氧缩合
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十五分会：物理有机
- 语种：中文
- 分类号：O621.251
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十五分会 ; 物理有机
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：402k
- 原文格式：D
- 会议级别：全国
摘要
有机磷催化的反应在有机合成中具有重要的意义,其中利用有机磷作为氧原子转移的反应是其中的一个热点课题~([1])。然而转移后的副产物的循环利用,则成为一个阻碍其应用的重要因素。采用一定的还原剂对该磷氧化合物的进行还原,是一种可行的和环保的策略,因而得到了越来越多有机磷化学家的关注~([2])。最近,赵等研究了在(PⅢ)/P(V)=O循环催化下的α-酮脂和羧酸的脱氧缩合反应~([3])。根据文献报道,我们在CAM-B3LYP/6-31G(d,p)水平上研究了该反应的反应机理,其反应过程包括:催化剂与α-酮脂的络合,氧原子转移,催化剂再生。通过分析反应自由能图,我们可以得到其中磷氧化合物的还原这一步是决速步骤,其自由能垒为28.5kcal/mol,说明在实验条件下可以完成。
The phosphetane-catalyzed oxygen-atom-transfer reaction is fascinating and hot research topic, since it is widely applied in organic synthesis. However, it is difficult to deal with the co-product P(V)=O. Recently, the method utilizing the cycling of P(Ⅲ)/P(V)=O to catalyze deoxygenative condensation of esters and carboxylic acids has been reported, but its detailed mechanism is still unknown. Our DFT calculation confirmed that the reaction involves three typical steps: the addition of phosphetane and α-ketoester, oxygen-atom-transfer and the reduction of P(V)=O, in which the free-energy barrier for the rate-controlling step is 28.5 kcal/mol.
The phosphetane-catalyzed oxygen-atom-transfer reaction is fascinating and hot research topic, since it is widely applied in organic synthesis. However, it is difficult to deal with the co-product P(V)=O. Recently, the method utilizing the cycling of P(Ⅲ)/P(V)=O to catalyze deoxygenative condensation of esters and carboxylic acids has been reported, but its detailed mechanism is still unknown. Our DFT calculation confirmed that the reaction involves three typical steps: the addition of phosphetane and α-ketoester, oxygen-atom-transfer and the reduction of P(V)=O, in which the free-energy barrier for the rate-controlling step is 28.5 kcal/mol.
引文
[1]Zhao,W.;Fink,D.M.;Labutta,C.A.;Radosevich,A.T.Org.Lett.2013,15:3090.
[2]O’Brien,C.J.;Tellez,J.L.;Nixon,Z.S.;Kang,L.J.;Angew.Chem.,Int.Ed.2009,48:6836.
[3]Zhao,W.;Yan,P.K.;Radosevich,A.T.J.Am.Chem.Soc.2015,137:616-619
[2]O’Brien,C.J.;Tellez,J.L.;Nixon,Z.S.;Kang,L.J.;Angew.Chem.,Int.Ed.2009,48:6836.
[3]Zhao,W.;Yan,P.K.;Radosevich,A.T.J.Am.Chem.Soc.2015,137:616-619