Trichloroacetimidates are useful reagents for the synthesis of esters under mild conditions that do not require an exogenous promoter. These conditions avoid the undesired decomposition of substrates with sensitive functional groups that are often observed with the use of strong Lewis or Brønsted acids. With heating, these reactions have been extended to benzyl esters without electron donating groups. These inexpensive and convenient methods should find application in the formation of esters in complex substrates.

A one-pot synthesis of dihydronaphthalenes and arylnaphthalenes from epoxides and common dipolarophiles is described. The reaction proceeds through photoredox activation of epoxides to carbonyl ylides, which undergo concerted [3 + 2] dipolar cycloaddition with dipolarophiles to provide tetrahydrofurans or 2,5-dihydrofurans. In the same flask, acid promoted rearrangement affords densely functionalized dihydronaphthalenes and arylnaphthalenes, respectively, in an overall redox-neutral sequence of transformations. Succinct total synthesis (4−6 steps) of pycnanthulignene B and C and justicidin E are reported.

4-Acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate (Bobbitt's salt) effectively activates electron rich alkenes and promotes the addition of anilines. This transformation provides a direct, transition metal free method for amino-oxidation of alkenes under mild conditions. The relative stereochemistry of the amino-oxidation is influenced by solvent effects, with both the syn and anti amino-oxidation products being accessible from identical starting materials. File list (3)download file view on ChemRxiv AminoOx-Manuscript.pdf (582.97 KiB) download file view on ChemRxiv AminoOx-SuppInfo.pdf (6.39 MiB) download file view on ChemRxiv CCDC2031980.cif (0.96 MiB)

A simple, one-step transformation to produce 8,9-dihydrocannabidiol (H2CBD) and related “neocannabinoids” via controlled Friedel-Crafts reactions is reported. Experimental and computational studies probing the mechanism of neocannabinoid synthesis from cyclic allylic alcohol and substituted resorcinol reaction partners provide understanding of the kinetic and thermody-namic factors driving regioselectivity for the reaction. Herein, we present a reaction scope for neocannabinoid synthesis including the production of both normal and abnormal isomers under both kinetic and thermodynamic control. Discovery and optimization of this one-step protocol between various allylic alcohols and resorcinol derivatives is discussed and supported with density-functional theory (DFT) calculations.

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