CN-121974934-A - High-efficiency synthesis D2Method for symmetrical chiral conjugated carbon nano ring

Abstract

The invention discloses a method for efficiently synthesizing a D 2 symmetrical chiral conjugated carbon nano-ring, which takes planar chiral cyclic diamine as a starting point, obtains an intermediate D 2 - (P) -PtNR3 with a yield of 86% through pre-bending condensed ring units and platinum-mediated cyclization, obtains a target chiral conjugated nano-ring molecule D 2 - (P) -NR3 with a high yield of 75% after Pt is removed, and simultaneously obtains an enantiomer D 2 - (M) -NR3 with the same synthesis method and a high yield. The synthesis method solves the problems of low yield, difficult chiral control, complicated separation and purification and the like in the traditional macrocyclic synthesis.

Inventors

• DING ZHENG
• ZHU MANZHOU

Assignees

• 安徽大学

Dates

Publication Date

20260505

Application Date

20260126

Claims (8)

1. 1. A method for efficiently synthesizing D 2 symmetrical chiral conjugated carbon nano-rings is characterized by comprising the following steps: step 1, reacting a starting material 1 or a starting material 2 with 2, 5-dibutoxy terephthaloyl chloride to obtain an intermediate I or an intermediate I'; ; ; step 2, reacting the intermediate I or the intermediate I 'with 2-thiophenyl chloride to obtain an intermediate II or an intermediate II'; ; step 3, performing ring closure reaction on the intermediate II or the intermediate II 'to obtain an intermediate III or an intermediate III'; ; step 4, reacting the intermediate III or the intermediate III 'with a format reagent, and then reacting with tributyl tin chloride to obtain an intermediate IV or an intermediate IV'; ; Step 5, reacting the intermediate IV or the intermediate IV' with dichloro (1, 5-cyclooctadiene) platinum (II) to obtain D 2 - (P) -PtNR3 or D 2 - (M) -PtNR3; ; Step 6:D 2 - (P) -PtNR3 or D 2 - (M) -PtNR3 is reacted with triphenylphosphine to give D 2 - (P) -NR3 or D 2 - (M) -NR3; 。
2. 2. the method according to claim 1, characterized in that: The reaction of step 1 is carried out in the presence of a basic substance a, which is triethylamine.
3. 3. The method according to claim 1, characterized in that: In step 2, the reaction is carried out in the presence of a basic substance a, which is triethylamine. .
4. 4. The method according to claim 1, characterized in that: in the step 3, the reaction is carried out in the presence of a catalyst A, wherein the catalyst A comprises palladium acetate and tricyclohexylphosphine tetrafluoroborate, and the molar ratio of the palladium acetate to the tricyclohexylphosphine tetrafluoroborate is 3:2.
5. 5. The method according to claim 1, characterized in that: In step 3, the reaction is performed in the presence of an alkaline substance B including any one of potassium acetate, potassium carbonate or cesium carbonate.
6. 6. The method according to claim 1, characterized in that: In the step 4, the reaction is carried out in the presence of an alkaline substance C, wherein the alkaline substance C is TMPMgCl.LiCl.
7. 7. The method according to claim 1, characterized in that: In the step 5, the molar ratio of the intermediate IV or the intermediate IV' to dichloro (1, 5-cyclooctadiene) platinum (II) and triphenylphosphine is 1:2:15.
8. 8. The method according to claim 1, characterized in that: In step 6, the molar ratio of D 2 - (P) -PtNR3 or D 2 - (M) -PtNR3 to triphenylphosphine is 1:15.

Description

Method for efficiently synthesizing D 2 symmetrical chiral conjugated carbon nano-ring Technical Field The invention belongs to the technical field of organic synthesis, and particularly relates to a method for efficiently synthesizing a D 2 symmetrical chiral conjugated carbon nano-ring. Background The chiral carbon nano-ring is an important research object of leading edge material chemistry due to unique photoelectric properties and chiral microenvironment. However, its efficient, stereospecific synthesis faces serious challenges. The entropy penalty inherent in macrocyclization reactions results in low yields, often requiring highly diluted conditions to suppress side reactions, and limited synthesis efficiency. For chiral systems, chiral configuration is difficult to maintain during cyclization and racemization is easy to occur. Asymmetric synthesis strategies are demanding, while chiral resolution of the racemic product is extremely cumbersome due to the close nature of the enantiomers. In addition, the target macrocycle often coexists with linear or cyclic byproducts, and separation and purification are difficult. The prior method is difficult to synchronously realize high yield, high chiral selectivity and simple post-treatment, and forms a key bottleneck for development in the field. To improve cyclisation efficiency, assembly strategies based on coordination orientation of transition metals (such as platinum) are widely explored. However, the selectivity of the existing platinum-mediated cyclization reaction is generally poor, a polycyclic mixture is easily generated, and the target dimeric ring is difficult to obtain with high selectivity. The root is that the geometric configuration of the conventional construction unit cannot be well matched with the coordination bond angle (such as Pt (II) to 90 degrees) of the metal center. Furthermore, the reported chiral macrocycles have to be expanded in their performance in functional applications, especially as supramolecular hosts. Although fullerenes are classical guests, existing hosts often exhibit single binding modes, limited binding forces, and host-guest complexes tend to simply accumulate, and it is difficult to drive the formation of diverse higher order ordered assembled structures (e.g., helical arrays, one-dimensional channels, etc.) according to guest characteristics, limiting their application potential in advanced chiral material construction. In summary, the prior art has clear blank that a general strategy for synchronously synthesizing specific chiral carbon nano rings with high yield and high chiral selectivity is lacking, and the product has strong binding capacity and diversified high-order assembly functions. Disclosure of Invention The invention provides a method for efficiently synthesizing a D 2 symmetrical chiral conjugated carbon nano-ring aiming at the defects of the prior art. According to the invention, a specific rigid framework with a large bending angle and a stable chiral source are integrated in a construction unit in advance through molecular design, so that the geometric structure of the rigid framework is matched with the coordination requirement of a target metal cyclization step in a 'pre-matching' manner, thereby leading the reaction to generate a target dimeric platinum intermediate with high selectivity from the source, and finally, the target dimeric platinum intermediate is efficiently converted into a chiral pure carbon nano ring. The D 2 symmetrical chiral conjugated carbon nano ring has a molecular formula of C 108H112N8O12S4, and specifically comprises two chiral configurations of D 2 - (P) -NR3 and D 2 - (M) -NR3, and the structure is shown as follows: Where n=2, and the arc represents a single bond. The invention discloses a method for efficiently synthesizing a D 2 symmetrical chiral conjugated carbon nano-ring, which comprises the following steps: step 1, reacting a starting material 1 or a starting material 2 with 2, 5-dibutoxy terephthaloyl chloride to obtain an intermediate I or an intermediate I'; step 2, reacting the intermediate I or the intermediate I 'with 2-thiophenyl chloride to obtain an intermediate II or an intermediate II'; step 3, performing ring closure reaction on the intermediate II or the intermediate II 'to obtain an intermediate III or an intermediate III'; step 4, reacting the intermediate III or the intermediate III 'with a format reagent, and then reacting with tributyl tin chloride to obtain an intermediate IV or an intermediate IV'; Step 5, reacting the intermediate IV or the intermediate IV' with dichloro (1, 5-cyclooctadiene) platinum (II) to obtain D 2 - (P) -PtNR3 or D 2 - (M) -PtNR3; Step 6:D 2 - (P) -PtNR3 or D 2 - (M) -PtNR3 was reacted with triphenylphosphine to give D 2 - (P) -NR3 or D 2 - (M) -NR3. Step 1 is carried out in a solvent a selected from dichloromethane or chloroform. In step 1, the molar ratio of the starting material 1 or the starting material 2 to the 2