Here we report a strategy for carbonyl addition with unactivated alkenes using an organic photocatalyst on both aldehyde and ketone substrates. This protocol grants us a good alternative to the traditional Barbier–Grignardallylation that exhibits poor functional group tolerance. With this method the stoichiometric use of metals can be avoided, high atom economy can be achieved and fewer by-products
The zinc–mediated aqueous Barbier–Grignardreaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90%) and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic
organic molecules with various ketones through sp3 C–H bond activation. The thiyl radical generated via single-electron oxidation of TPI by the excited photoredox catalyst abstracted a hydrogen atom from organic molecules such as toluene, benzyl alcohol, alkenes, aldehydes, and THF. The thus-generated carbon-centered radical species underwent addition to ketones and aldehydes. This intrinsically unfavorable
Ultraviolet Irradiation of Carbonyl Compounds in Cyclohexene and 1-Hexene
作者:Jerald S. Bradshaw
DOI:10.1021/jo01339a053
日期:1966.1
A Novel Catalytic Route to Polymerizable Bicyclic Cyclic Carbonate Monomers from Carbon Dioxide
作者:Chang Qiao、Wangyu Shi、Arianna Brandolese、Jordi Benet‐Buchholz、Eduardo C. Escudero‐Adán、Arjan W. Kleij
DOI:10.1002/anie.202205053
日期:2022.7.4
A novel catalytic approach for the preparation of polymerizable bicyclic carbonates allows the synthesis of a wide range of unique heterocycles. The stereochemical configuration of the epoxy alcohol substrate plays a crucial role, determining the chemoselectivity profile of this coupling manifold. The synthetic potential of these bicyclicsix-membered carbonates was examined, and their successful ring-opening