Recent Advances in Ring‐Opening Functionalization of Cycloalkanols by C–C σ‐Bond Cleavage

Abstract

Cycloalkanols prove to be privileged precursors for the synthesis of distally substituted alkyl ketones and polycyclic aromatic hydrocarbons (PAHs) by virtue of cleavage of their cyclic C-C bonds. Direct functionalization of cyclobutanols to build up other chemical bonds (e. g., C-F, C-Cl, C-Br, C-N, C-S, C-Se, C-C, etc.) has been achieved by using the ring-opening strategy. Mechanistically, the C-C cleavage of cyclobutanols can be involved in two pathways: (a) transition-metal catalyzed β-carbon elimination; (b) radical-mediated 'radical clock'-type ring opening. The recent advances of our group for the ring-opening functionalization of tertiary cycloalkanols are described in this account.

C-C and C-H bond cleavage reactions in acenaphthylene aromatic molecule, an ab-initio density functional theory study

“…Accurate evaluation of the reaction path is required for the quantitative description of the C-C and C-H bond cleavage [14,15]. For this purpose, we chose the evaluation of the total energy of the reacting molecule as function of the corresponding C-C or C-H bond length, where both singlet and triplet electron configurations are considered.…”

“…Due to their industrial importance, the study of the thermal degradations of polycyclic aromatic hydrocarbons (PAH) had been a subject for numerous experimental and theoretical investigations [1][2][3][4][5][6][7][8][9][10][11][12][13]. In previous papers, we reported quantum mechanically calculated structures and energies of the transition states (TS) and reaction products (RP) of the C-C and C-H bond cleavage reactions for a number of poly-aromatic hydrocarbon molecules [14][15][16][17][18][19][20][21]. We applied for these treatments the ab-initio Density Functional Theory (DFT) method [23][24][25][26][27].…”

Radical Reactions for the Synthesis of 3‐Substituted Chroman‐4‐ones

“…For example, a variety of transition‐metal‐catalyzed ring‐opening cross‐coupling reactions have been developed . In the past years, cyclopropanols have been reported as radical precursors through C–C bond cleavage giving β‐carbonyl alkyl radicals for the ring‐opening/cascade radical coupling strategy . Recently, the tandem cyclization of o ‐allyloxybenzaldehydes 67 and cyclopropanols 68 to synthesize 1,6‐dicarbonyl containing chroman‐4‐ones 69 was independently reported by Wei's group and Wang's group almost at the same time (Scheme ).…”

Visible light-promoted ring-opening functionalization of unstrained cycloalkanolsviainert C–C bond scission

“… 1 Strained cycloalkanols such as cyclopropanols and cyclobutanols have emerged as privileged precursors for the preparation of β- and γ-substituted ketones through radical-mediated ring-opening functionalization. 2 , 3 Recently, we have consecutively reported the ring-opening functionalization of cyclobutanols to construct various chemical bonds, e.g. , C–F, C–Cl, C–N, C–S, C–C, etc.…”