Alkoxy, Halogenated Pyridine And Its Diphenyl Phosphine Derivatives Synthesis Of Research

It is more and more important to investigate organic asymmetric synthesis with the development of our society. One of the most significant breakthroughs in this field is the asymmetric catalysis using chiral catalysts. Chiral substance is used in small amounts which usually could be isolated after the reaction and reused, and of further importance, it is applied to lots of substrates. Therefore, it is the most potential that asymmetric synthesis controlled by chiral catalysts is used in the industry.The chiral catalysts play the key role in the asymmetric catalytic synthesis, in which the chiral ligands are essential. So far, more than one thousand chiral nonracemic diphosphines , as well as the efficiency of catalysts, have been reported. Especially, tremendous success has been achieved in the use of heteroarylphosphines in Rh- or Ru-catalyzed asymmetric reactions. On the other hand, pyridyl-cantaining compounds constitute an important a class of synthetic and natural products, involved in a great deal of chiral substance. The solubility of the pypridylphosphine ligands, either in aqueous or in organic solvents, could be easily controlled by adjusting the acidity of the solution. As demonstrated above, the possibility of designing new chiral pyridylphosphine remains to be an area of active research.As an effort to expand the scope of the pyridylphosphine ligands, we study the intermediate, i.e. pyridylphosphine bromide with different substituents. In this thesis, we will describe the synthesis of alkyloxypyridine bromide and its diphenylphosphine derivation, and discuss how to improve the selectivity of each reaction. A variety of substituents were applied to replace the H atom of pyridyl group, which may introduce interesting chemistry. The synthesis route is outlined as follows. ① First, 2,6-dialkyloxypyridine(alkyloxyl: -OMe, -OEt, -Oi-Pr, cyclohexoxyl) was prepared from 2,6-dichlorpyridine, including pyridine with two same alkyloxyls and that with two different alkyloxyls. The former class of compounds were performed in the high press(15~20atm/150~160oC), while the latter first in the ambient press(70~80℃) and then high press (15~20atm/150~...