CAS: 1097733-23-7; Bromo(2-Pyridyl)Carbene

📜3-Bromo-3-(2-Pyridyl)Diazirine 以 异辛烷 用作溶剂,化学反应生成2-溴甲基吡啶
参考文献:Absolute Reactivity Of Halo(Pyridyl)Carbenes
标题:Absolute Reactivity Of Halo(Pyridyl)Carbenes
摘要:A Comprehensive Series Of Halo(Pyridyl)Carbenes Was Generated By Laser Flash Photolysis Of The Appropriate Diazirines. Only The Chloro-And Bromo(2-Pyridyl)Carbenes And The Chloro-And Bromo(3-Pyridyl)Carbenes Could Be Directly Observed,But The Reactivity Of All Nine Halo(Pyridyl)Carbenes Could Be Directly Studied Using The Standard And A Modified Pyridine-Ylide Approach. The Carbenes Were All Ambiphilic,Being Highly Reactive Toward Both Electron-Rich And Election-Deficient Alkenes. Second-Order Rate Constants For These Reactions Ranged From 2.9 X 10(6) To 3.5 X 10(9) M-1 S(-1) And Depended On Both The Position Of The Nitrogen Atom Within The Pyridine Ring And The Nature Of The Halogen Group,As Well As The Electrophilicity Or Nucleophilicity Of The Alkene. A Reactivity Trend With Respect To The Location Of The Nitrogen Within The Pyridine Ring Was Observed,With The 4-Pyridyl Carbenes Being The Most Reactive Followed By The 2-Pyridylcarbenes And Then The 3-Pyridylcarbenes Being The Least Reactive. This Observed Reactivity Trend Is Consistent With The Pyridyl Ring Acting As An Overall Electron-Withdrawing Group. The Results Also Show That Resonance Delocalization Of Electron Density Into The Nitrogen Atom Of The 4-Pyridyl-And 2-Pyridylcarbenes In The Transition State Significantly Reduces The Effect Of The Adjacent Halogen (F,Cl,Or Br) On The Reactivity Of The Pyridyl Carbenes With A Series Of Alkenes.
Doi:10.1021/jo802132Z