Modular synthesis of oligoacetylacetones via site-selective silylation of acetylacetone derivatives

Abstract

Aliphatic oligoketones with tailored carbonyl and substituent sequences were modularly synthesized utilizing site-selective formation of enol silyl ethers. Their unique conformational preferences in solid-state were revealed by X-ray crystallography.

Determination of the critical chain length for macromolecular crystallization using structurally flexible polyketones

“…In this work, we focused on aliphatic polyketones consisting of 3,3-dimethylpentane-2,4-dione (1) as the monomer. [42][43][44][45][46] Recently, these polyketones have received attention as lithium ion conducting materials 47 and as structurally exible synthetic precursors for generating metal ion adsorbents, 48 pconjugated chromophores, [49][50][51][52] and anion-binding hosts. 53 Furthermore, these polyketones have advantages in the stepwise synthesis of discrete oligomers.…”

Contracted porphyrins and calixpyrroles: synthetic challenges and ring-contraction effects

“…To realize the ring tightening synthesis of calix [3]pyrrole, our group has developed stepwise oligomerization 76,77 and macrocyclization 78 Calix [3]pyrrole 60 was rst synthesized in 41% yield through a triple Paal-Knorr reaction using cyclic hexaketone 59 and ammonium acetate (Scheme 9). An important factor in the successful synthesis of 60 is the use of non-acidic reaction conditions because acids commonly used under Rothemund-Lindsey conditions, such as TFA, trigger rapid, quantitative strain-induced ring expansion of 60, which will be discussed in Section 3.…”

“…To realize the ring tightening synthesis of calix[3]pyrrole, our group has developed stepwise oligomerization 76,77 and macrocyclization 78 of acetylacetone derivative 53 . Compound 53 undergoes mono- and bis-selective silylation in the presence of 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and triethylamine to give 54 and 55 , 79 respectively.…”