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CN-122010998-A - Four-coordinated boron-oxygen heterocyclic compound and preparation method thereof

CN122010998ACN 122010998 ACN122010998 ACN 122010998ACN-122010998-A

Abstract

A tetra-coordinated boron-oxygen heterocyclic compound and a preparation method thereof belong to the technical fields of pharmaceutical chemical intermediates and related chemistry. The method takes bis (pentafluorophenyl) borane dimethyl sulfide complex [ (C 6 F 5 ) 2 BH•SMe 2 ] as a boron source, firstly, the bis (pentafluorophenyl) borane dimethyl sulfide complex and an eneyne compound undergo a hydroboration reaction in situ to generate a three-coordination alkenyl boron dienophile intermediate, and then, the three-coordination alkenyl boron dienophile intermediate and the alkynone compound undergo a Diels-Alder reaction with inverse electron demand to synthesize a series of four-coordination boron oxygen heterocyclic compounds.

Inventors

  • WANG AILING
  • HU BO
  • WANG TONGDAO
  • MEI YONGQIANG

Assignees

  • 大连大学

Dates

Publication Date
20260512
Application Date
20260410

Claims (9)

  1. 1. The four-coordinated boron-oxygen heterocyclic compound is characterized by having a structural general formula: ; Wherein R 1 is selected from phenyl, substituted phenyl or cycloalkyl, R 2 is selected from C1-C6 alkyl, phenyl, substituted phenyl, cycloalkyl, aryl, heteroaryl, -NR 3 R 4 , wherein R 3 、R 4 is each independently selected from hydrogen, C1-C6 alkyl.
  2. 2. The four-coordinated boroxine compound according to claim 1, wherein the substituted phenyl is C1-C6 alkyl, halogen or C1-C6 alkoxy substituted phenyl, cycloalkyl is 3-8 membered cycloalkyl, aryl is naphthyl, anthryl, phenanthryl, heteroaryl is pyridyl, pyrrolyl, furyl, thienyl, imidazolyl, pyrazolyl, pyrimidinyl, pyrazinyl, indolyl, benzofuranyl, benzothienyl.
  3. 3. The four-coordinated boron-oxygen heterocyclic compound according to claim 2, wherein R 1 is one selected from phenyl, bromophenyl, chlorophenyl, p-methylphenyl, p-propylphenyl, p-methoxyphenyl, o-methoxyphenyl, bonded methoxyphenyl, cyclopropyl, cyclobutyl and cyclohexyl; R 2 is selected from methyl, ethyl, tert-butyl, phenyl, bromophenyl, chlorophenyl, p-methylphenyl, p-propylphenyl, p-methoxyphenyl, o-methoxyphenyl, bonded methoxyphenyl, cyclopropyl, cyclobutyl, cyclohexyl, naphthyl, furyl, thienyl, dimethylamino.
  4. 4. A four-coordinated boron-oxygen heterocyclic compound according to claim 3, wherein R 1 is selected from phenyl, 4-methoxyphenyl, 4-methylphenyl, 4-propylphenyl, 4-chlorophenyl, 4-bromophenyl, cyclopropyl, R 2 is selected from phenyl, cyclopropyl, 2-naphthyl, 2-furyl, 2-thienyl, 4-methoxyphenyl, N-dimethyl, tert-butyl.
  5. 5. The method for preparing the tetra-coordinated boron-oxygen heterocyclic compound according to any one of claims 1 to 4, which is characterized in that a series of tetra-coordinated boron-oxygen heterocyclic compounds are synthesized by taking a bis (pentafluorophenyl) alkenyl boron intermediate and an alkynone compound as raw materials, wherein the synthetic route is as follows: ; The definition of R 1 and R 2 in compound 1 is the same as that of R 1 and R 2 in compound 2.
  6. 6. The method for preparing the tetra-coordinated boron-oxygen heterocyclic compound, according to claim 5, is characterized in that the preparation method comprises the steps of dissolving bis (pentafluorophenyl) borane dimethyl sulfide complex [ (C 6 F 5 ) 2 BH·SMe 2 ] in an organic solvent, adding 2-methyl-1-butene-3-alkyne, stirring at room temperature for reaction to generate a tri-coordinated alkenyl boron intermediate, adding acetylenic compound 1, reacting at 20-100 ℃ for 8-20 hours, and carrying out post-treatment after the reaction is finished to obtain a target product.
  7. 7. The method for producing a tetra-coordinated boron-oxygen heterocyclic compound according to claim 6, wherein the molar ratio of the bis (pentafluorophenyl) borane dimethyl sulfide complex, 2-methyl-1-butene-3-yne to the compound 1 is 1 (1 to 1.2): 1 to 1.2.
  8. 8. The method for preparing a tetra-coordinated boron-oxygen heterocyclic compound according to claim 6, wherein the organic solvent is one or more selected from the group consisting of dichloromethane, chloroform, 1, 2-dichloroethane, toluene and tetrahydrofuran.
  9. 9. The method for preparing the tetra-coordinated boron-oxygen heterocyclic compound according to claim 6, wherein the post-treatment step is characterized in that the solvent is removed in vacuum after the reaction is finished, a mixed solvent of ethanol and n-hexane is added into the system under the protection of inert gas, the solid is stirred and separated out, the solid is filtered, washed by n-hexane and dried to obtain a pure target product.

Description

Four-coordinated boron-oxygen heterocyclic compound and preparation method thereof Technical Field The invention relates to a preparation method of a novel tetra-coordinated boron-oxygen heterocyclic compound, belongs to the technical field of pharmaceutical chemical intermediates and related chemistry, and particularly relates to a preparation method of a tetra-coordinated boron-oxygen heterocyclic compound based on a Diels-Alder reaction of inverse electron requirements of bis (pentafluorophenyl) alkenyl boron and alkynone and using the bis (pentafluorophenyl) alkenyl boron intermediates and the alkynone compound as raw materials. Background The four-coordination organic boron compound has wide application prospect in the fields of organic synthesis, material science, pharmaceutical chemistry and the like due to the unique electronic structure and reactivity. Compared with common tridentate borates, the tetradentate boron compound has higher stability and a unique reaction mode, and negative charges on boron atoms of the tetradentate boron compound can be delocalized through a conjugated system to form a 'boron center negative ion' species with specific reactivity. Among them, bis (pentafluorophenyl) borane derivatives have unique electronic properties due to their strongly electron-withdrawing pentafluorophenyl groups, which provides a possibility for controlling the reactivity. The Diels-Alder reaction with inverse electron demand is used as an important method for efficiently constructing a six-membered ring skeleton, and has unique application value in the field of organic synthesis. Unlike the Diels-Alder reaction of normal electron demand, the IEDDA reaction involves a [4+2] cycloaddition between electron-deficient diene and electron-rich dienophile, and the reversal of this electron demand makes it complementary to classical reactions in reaction mode and product structure, providing a unique synthetic strategy for the construction of complex polycyclic backbones. However, studies of the IEDDA reaction of bis (pentafluorophenyl) alkenyl boron as dienophile with alkynone have not been reported so far, and the rules of reactivity, regioselectivity and stereoselectivity are not clear. Therefore, the development of the preparation method of the tetra-coordinated boron-oxygen heterocyclic compound with high efficiency, mildness and good selectivity has important significance. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a tetra-coordinated boron-oxygen heterocyclic compound and a preparation method thereof, the method uses a bis (pentafluorophenyl) borane dimethyl sulfide complex as a boron source, firstly, reacting with eneyne to generate a tridentate alkenyl boron intermediate, and further reacting with alkynone to generate Diels-Alder reaction with inverse electron requirement to synthesize the tetra-coordinated boron-oxygen heterocyclic compound. The method has the advantages of mild reaction conditions, good selectivity, high yield, wide substrate application range, environmental friendliness and the like. The invention has great application value and social and economic benefits. The technical scheme adopted by the invention is that the four-coordinated boron-oxygen heterocyclic compound has the structural general formula: Wherein R 1 is selected from phenyl, substituted phenyl or cycloalkyl, R 2 is selected from C1-C6 alkyl, phenyl, substituted phenyl, cycloalkyl, aryl, heteroaryl, -NR 3R4, wherein R 3、R4 is each independently selected from hydrogen, C1-C6 alkyl. Further, the substituted phenyl is C1-C6 alkyl, halogen or C1-C6 alkoxy substituted phenyl, the cycloalkyl is 3-8 membered cycloalkyl, the aryl is naphthyl, anthryl and phenanthryl, and the heteroaryl is pyridyl, pyrrolyl, furyl, thienyl, imidazolyl, pyrazolyl, pyrimidinyl, pyrazinyl, indolyl, benzofuranyl and benzothienyl. Further, R 1 is selected from one of phenyl, bromophenyl, chlorophenyl, p-methylphenyl, p-propylphenyl, p-methoxyphenyl, o-methoxyphenyl, bonded methoxyphenyl, cyclopropyl, cyclobutyl and cyclohexyl; R 2 is selected from methyl, ethyl, tert-butyl, phenyl, bromophenyl, chlorophenyl, p-methylphenyl, p-propylphenyl, p-methoxyphenyl, o-methoxyphenyl, bonded methoxyphenyl, cyclopropyl, cyclobutyl, cyclohexyl, naphthyl, furyl, thienyl, dimethylamino. The preparation method of the four-coordinated boron-oxygen heterocyclic compound is characterized in that a bis (pentafluorophenyl) alkenyl boron intermediate and an acetylenic ketone compound are used as raw materials to synthesize a series of four-coordinated boron-oxygen heterocyclic compounds: The synthetic route is as follows: ; The definition of R 1 and R 2 in compound 1 is the same as that of R 1 and R 2 in compound 2. Further, the preparation method comprises the steps of dissolving bis (pentafluorophenyl) borane dimethyl sulfide complex [ (C 6F5)2BH·SMe2 ] in an organic solvent, adding 2-methyl-1-butene-3-alkyne, stir