Value Addition to α‐Position of Carbonyl: Synthesis of 2‐Arylidene and Halocycloalkanones

• Published in: ChemistrySelect (Weinheim) 2024-09, Vol.9 (35), p.n/a
• Main Authors: Bhatt, Gaurang J., Kahar, Nidhi, Purohit, Ashish C., Deota, Pradeep T., Dhasmana, Yogesh, Chopra, Deepak
• Format: Article
• Language: English
• Subjects: Claisen-Schmidt condensation; Dodecahydrotriphenylene; Halocycloalkanones; Trindane; α,β-enones
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202401863

Benzocyclotrimers (BCTs) like trindane and dodecahydrotriphenylene (DDHTP) have attracted attention as key components for the construction of higher polycyclic aromatic hydrocarbons due to their aesthetic architecture that is useful in developing beautiful carbocycles of higher order. However, there are limited reports on these ring systems since their functionalization is a formidable task. Our personal engagement with these scaffolds prompted us to explore the synthesis of their synthetically useful derivatives. Herein, we report syntheses of a new series of their derivatives by exploiting the α–position of these cycloalkanones using classical Claisen‐Schmidt condensation reaction as well as simple and practical α‐Csp3–H halogenation with suitable halogenating agents. An approach for the α‐Csp3‐H functionalization of aesthetic carbocycles, trindane‐1‐one and dodecahydrotriphenylene‐1‐one is presented. A library of derivatives of these carbocycles has been synthesized using Claisen‐Schmidt condensation and α‐halogenation reactions under mild conditions and shorter reaction times yielding good to excellent results. Fifteen examples of Claisen‐Schmidt condensation with aromatic aldehydes and nine examples of α‐halo derivatives using various halogenating agents are reported.