Metal-free Phosphorylation of C(sp~3)-H and S-H Bonds
Author:Wen Chun Xiao
Supervisor:zhang chen qian
Organophosphorus compounds are widely used in medicinal chemistry,pesticide chemistry,materials science,and as ligands,catalysts,etc.,while their traditional synthesis methods generally use phosphorus halogen reagents,nucleophilic substitution of organometallic reagents,but such reactions often face moisture-sensitive,requires pre-functionalization,harsh reaction conditions,and high toxicity limits.Based on the oxidative coupling of our group to construct the reaction of phosphorus-carbon,phosphorus-fluorine and phosphorus-oxygen bonds,the method of constructing phosphorus-carbon and phosphorus-heterobond for the development of simple,efficient and atomic economic strategies has been further explored.(1)We have developed a method for the synthesis of allylphosphonates use 1,3-diarylpropenes with P(O)H compounds by cross-dehydrogenation coupling at room temperature,a series of allylphosphonates were synthesized by this method.The substrates have a wide range of functional group tolerances and good yields.The corresponding conversion was achieved in scal-up reaction at a yield of 72%.The conversion strategy was convenient,efficient,and green.Finally,the possible reaction mechanism was proposed,it provides a theoretical basis and experimental basis for the green and efficient construction of C(sp3)-P bonds under mild conditions.(2)We have developed a method for the synthesis of cyclohepta-2,4,6-trien-l-ylphosphonates use cycloheptatriene with P(O)H compounds by cross-dehydrogenation coupling at room temperature,the substrates have a wide range of functional group tolerances and good yields,a series of cyclohepta-2,4,6-trien-l-ylphosphonates were synthesized by this method.The Michaelis-Arbuzov-type reaction of P(Ⅲ)compounds afford a facile access to dialkyl/diaryl tropylphosphonates.Based on the first part of the research,the possible reaction mechanism was proposed.We have developed a simple,efficient,green synthesis method for cycloheptatriene phosphorylation.(3)We have developed a method for the synthesis of phosphorothioates via halogen-and metal-free K2CO3-promoted aerobic oxidative cross-coupling of trialkyl phosphites,dimethyl phenylphosphonite or methyl diphenylphosphinite with thiophenols using air as the oxidant at room temperature,this transformation provides a straightforward route to the construction of phosphorus-sulfur bonds with wide functional group compatibility,which affords phosphorothioates in up to 94%yield.The corresponding conversion was achieved in scal-up reaction at a yield of 65%.Finally,the possible reaction mechanism was proposed.At the same time,we have developed a novel and efficient oxidation of thiophenols with TBHP/TBAI under mild conditions.This method provides a simple and practical protocol for the synthesis of tert-butyl arylsulfinates with good functional group compatibility.it provides an alternative path for the synthesis of tert-butyl arylsulfinates.