Study On The Activationof C-H And N-H Bonds Of Aromatic Ketones And Secondary Amines

The functionalization of C-H bonds and N-H bonds of organic compounds havebecome a research hotspotin the field of organic synthesis.The activation of C-H bonds and N-H bonds can reduce the synthesis steps and the atomic utilization can be achieved.Therefore,this protocol opens a new avenue for the design of chemical synthesis.This paper mainly focus on the formation of bibenzo[b][1,4]thiazine derivatives using2,2'-disulfanediyldianilines and aromatic ketonesas as the starting materials and the C-C,C-N and C-S bonds can be constructed by theactivation of aromatic ketones C?sp³?-H bonds.Addiationally,the intermediate has also been captured by GC-MS and a possible mechanism was proposedwith control experiments.On the basis of the previous work,a varietyof?-2,2'-bi?3-phenyl-2H-1,4-benzothiazine?Z/EisomerswithC=C double-bonding were obtained by using I₂/DMSO and molecule oxygen as the oxidation systems.Additionally,four Pd-POMs compounds have been successfully synthesized via the combination of Pd?OAc?₂,N-imidazoles and POMs.Notably,these compounds show efficient catalytic activities for the oxidation of secondary aminesand the Suzuik-Miyaura cross-coupling reationsfor the C=N,C-C bonds formation.The main workof this paper are as follows:1.A series of bibenzo[b][1,4]thiazines with various functional groups has been synthesized by a free radical condensation reaction.Bibenzo[b][1,4]thiazines were obtained in moderate to good yield?54%-84%?through a one one-step reaction of readily available 2,2?-dithiodianiline and methyl aryl ketones with AIBN as radical initiator in HOAc.To gain insight into mechanism of this reaction,three control experiments were designed and monitored by gas chromatography/mass spectrometer.2.Based on the previous work,two series of dibenzo-benzenes with C=C bonds,cis-and trans-structures were successfully synthesized by using the molecular oxygen and I₂/DMSO oxidation systems,respectively.A total of 30[1,4]thiazine compounds were synthesized.All the synthesized products were characterized by ¹H NMR,¹³C NMR and HRMS.3.Four Pd-POMs compounds have been successfully synthesized via the combination of Pd?OAc?₂,N-imidazoles and POMs.They have been characterized by the single crystal X-ray diffraction and IR.Notably,these compounds show efficient catalytic activities for the oxidation of secondary amines?yield up to 99%?and the Suzuik-Miyaura cross-coupling reations?yield up to 99%?for the C=N,C-C bond formation.Moreover,the catalysts can be reused three times without losting its activity.