2. Electrochemical Benzylic C(sp3)-H Acyloxylation
Alexander P Atkins, Albert C Rowett, David M Heard, Joseph A Tate, Alastair J J Lennox Org Lett. 2022 Jul 22;24(28):5105-5108. doi: 10.1021/acs.orglett.2c01930. Epub 2022 Jul 13.
The development of sustainable C(sp3)-H functionalization methods is of great interest to the pharmaceutical and agrochemical industries. Anodic oxidation is an efficient means of producing benzylic cations that can undergo subsequent in situ nucleophilic attack to afford functionalized benzylic products. Herein, we demonstrate the suitability of carboxylic acids as nucleophiles to yield benzylic esters. This method employs a series of secondary benzylic substrates and functionalized carboxylic acids and is demonstrated on a gram scale in flow.
3. N-carboxy-L-aspartic anhydride benzyl ester
Hitoshi Kanazawa, Jun Magoshi Acta Crystallogr C. 2003 Mar;59(Pt 3):o159-61. doi: 10.1107/s0108270103002567. Epub 2003 Feb 28.
The structure of the title compound, benzyl (1,2,3,4-tetrahydro-2,5-dioxo-1,3-oxazol-4-yl)acetate, C(12)H(11)NO(5), has been determined in an attempt to explain the polymerization observed in the solid state. The molecules are linked by intermolecular hydrogen bonds between the imino group of the five-membered ring and an adjacent carbonyl O atom, along the c axis. Intramolecular hydrogen bonds are also formed, between the imino group and the carbonyl O atom of the ester group. The five-membered rings are arranged in a layer, sandwiched by layers incorporating the benzyl groups. This structure is thought to be preferable for the polymerization of the compound in the solid state, because the five-membered rings can react with each other in the layer.
