Visible-Light-Mediated Strategies for the Preparation of Oxime Ethers Derived from O-H Insertions of Oximes into Aryldiazoacetates.

Two visible-light-mediated O-H insertion protocols involving oximes and aryldiazoacetates leading to different products depending on the solvent employed are reported. In DCM, direct O-H insertion takes place. In THF, there is the additional incorporation of the ring-opened form of this solvent into the structure of the product.

Visible light-promoted reactions with diazo compounds: a mild and practical strategy towards free carbene intermediates.

Carbenes are important intermediates in organic chemistry and have been widely applied in various types of organic reactions, ranging from cycloaddition reactions and sigmatropic rearrangements to C-H functionalizations, thus allowing the rapid construction of densely functionalized molecules. Over the past decades, remarkable progress has been achieved in metal-catalyzed carbene transfer reactions. Nevertheless, realizing these transformations under milder and/or greener conditions is still highly desirable.

An Aminocatalyzed Michael Addition/Iron-Mediated Decarboxylative Cyclization Sequence for the Preparation of 2,3,4,6-Tetrasubstituted Pyridines: Scope and Mechanistic Insights.

A novel, scalable strategy for the preparation of 2,3,4,6-tetrasubstituted pyridines is described. This protocol has two steps: an aminocatalyzed addition of ketones to alkylidene isoxazol-5-ones, followed by an iron-mediated decarboxylative cyclization event. Mechanistic insights for both steps are provided based on HRMS-ESI(+) studies.