Nitrene Transfer Reaction in Pd Coordination Sphere

Research Project

Project/Area Number	59470015
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	有機化学一般
Research Institution	Faculty of Technology, Gunma University
Principal Investigator	MIGITA Toshihiko Professor Gunma University, 工学部, 教授 (40008412)
Project Period (FY)	1984 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥6,400,000 (Direct Cost: ¥6,400,000) Fiscal Year 1986: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1985: ¥900,000 (Direct Cost: ¥900,000) Fiscal Year 1984: ¥4,800,000 (Direct Cost: ¥4,800,000)
Keywords	Azide / unsaturated ether / unsaturated sulfide / Palladium( <II> ) catalysis / π-アリル錯体
Research Abstract	Azidoformate reacts with allylic ethers to give the <alpha> -imines specifically under catalyzed by Pd( <II> ). Mchanistic studies revealed the followings: 1) The same <alpha> -imines were formed almost quantitatively by non-catalyzed reaction of azide and the corresponding vinylic ethers. 2) Isomerization of an allylic ether to the corresponding vinylic ether was much slower than the above <alpha> -imine formation even in the presence of Pd( <II> ). 3) Rates of the <alpha> -imine formation were found to be first order each in the ether and in the azide. 4) Other unsaturated ethers such as homoallylic ethers also afforded to the <alpha> -imine by the catalyzed reaction with the azide. These ethers, however, isomerized to the corresponding allylic ethers under the reaction conditions. 5) Easiness of <alpha> -imine formation decreased as the following order; methanesulfonyl azide azido-formate phenyl azide stannyl azide. These results suggest the following mechanism: Isomerization of the allylic ether to the vinylic ether is promoted by the new Pd( <II> ) complex formed by exchanging the ligand PhCN to the azide molecule. The vinylic ether reacts with the azide to give <alpha> -imine via 1,3-dipolar addition followed by heterolysis of the triazine, involving with nitrogen evolution and 1,2-shift of hydrogen or alkyl groups. Reaction of allylic sulfides with azidoformate did not give <alpha> -imines, but the products derived from ylide formation between sulfide and nitrene, even in the presence of Pd( <II> ).