Synthesis of complex chiral architectures and extended structures via the transformation of 1,3-dicarbonyl compound derivatives

Abstract

1,3-Dicarbonyl compounds have the advantageous properties of easy accessibility and facile deprotonation of the ɑ-hydrogen between the carbonyl groups. This ease of deprotonation facilitates the generation of stabilized carboanions that can participate in various substitution reactions to synthesize complex molecules. Additionally, acyclic 1,3-dicarbonyl compounds can function as effective chelating agents to generate stable transition metal complexes. In Chapter 1, the research on 1,3-dicarbonyl compound derivatives is briefly summarized. Chapter 2 investigates a desymmetric cyanosilylation of acyclic 1,3-diketones. Chapter 3 describes a novel strategy for synthesizing transition metal-dibenzotetraaza[14]annulene (TM-DBTAA)-linked covalent organic frameworks (COFs) utilizing Ni(II) and Cu(II) malonaldehyde complexes as building blocks and reaction templates. Chapter 4 then presents an innovative approach where a Ni(II)-malonaldehyde complex-based coordination polymer is synthesized and used as a starting material to construct Ni(II)-DBTAA-linked linear polymers and 3-dimensional (3D) COFs. The diastereo- and enantioselective creation of vicinal stereocenters from easily accessible starting materials poses a challenge, and the development of acyclic quaternary stereocenters through intermolecular functionalization of linear diketones remains relatively unexplored. We introduce a desymmetric cyanosilylation reaction of acyclic 1,3-diketones where a bifunctional catalyst derived from dibutyl magnesium and a tetradentate ligand based on pipecolic acid catalyzes an asymmetric cyanosilylation of 1,3-diketones, leading to the formation of vicinal and acyclic tetrasubstituted carbons. This method allows for synthesizing silyl ethers of cyanohydrins with precise stereochemistry and diverse substituents. Additionally, these compounds have been successfully converted into more complex molecules such as heterocycles, triols, and fused rings. Incorporating the TM-DBTAA macrocycle into framework materials shows great promise for various applications, including conductive materials, catalysis, and sensors. However, limited methods for synthesizing TM-DBTAA-linked COFs hindered the construction of versatile COF structures with functionalized TM-DBTAA linkages. We present a new method for synthesizing TM-DBTAA-linked COFs and polymers, expanding the structural and functional diversity of this important material category. Ni(II) and Cu(II)-malonaldehyde complexes were employed as building blocks and reaction templates to synthesize TM-DBTAA-linked COFs in a condensation reaction with the o-phenylenediamine derivative 2,3,6,7,14,15-Hexaaminotriptycene (HAT) under mild conditions. This method allows for the creation of Ni(II) and Cu(II)-DBTAA-linked COFs with novel structure and accessible active metal centers. An innovative approach was also developed where a Ni(II)-malonaldehyde complex-based coordination polymer is synthesized and utilized as a starting material to construct Ni(II)-DBTAA-linked linear polymers and 3D COF. The functionalization of Ni(II)-DBTAA cores in the linear polymers can also be achieved by preinstalling functional groups onto o-phenylenediamine derivatives. This approach introduces a protocol by directly manipulating linear coordination polymers to generate novel structures unattainable by utilizing small-molecule starting materials. Furthermore, this synthetic strategy holds promise for further applications to create a range of Ni(II)-DBTAA-linked materials.