title: Multifold bond cleavage and formation between MeOH and quinoxalines (or benzothiazoles): synthesis of carbaldehyde dimethyl acetals.
abstract: A K(2)S(2)O(8)-mediated direct cross-coupling of quinoxalines (or benzothiazoles) with methanol leading to 2-quinoxalinyl (or 2-benzothiazolyl) carbaldehyde dimethyl acetals has been achieved. 2-Quinoxalinyl carbaldehyde dimethyl acetals were readily converted into 2-quinoxalinyl carbaldehydes in good to excellent yields under acidic conditions. Preliminary mechanistic studies suggest that the reaction proceeds via multifold bond cleavage and formation between methanol and N-heterocycles involving a dioxygen-participated radical process. This method allows for the synthesis of a variety of 2-quinoxalinyl (or 2-benzothiazolyl) carbaldehyde dimethyl acetals directly via cross-coupling of simple N-heterocyclic C-H bond and methanol under aldehyde-, acid-, and transition-metal-free conditions.
authors.affiliation: State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China. ykuiliu@zjut.edu.cn
authors.forename: Yunkui
authors.initials: Y
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhenyuan
authors.initials: Z
authors.lastname: Xu