Preparation and reactivity of new .beta.-nitrogen-functionalized vinylic organolithium compounds from secondary aliphatic allylamines
摘要:
Two new types of B-nitrogen-functionalized vinylic organolithium compounds have been prepared from secondary aliphatic allylamines through the temporary silylation of the amino group. The monoanionic intermediates 4, stable at -80 degrees C, are generated by a bromine-lithium exchange reaction and the dianionic derivatives 2, stable at room temperature, by a tin-lithium transmetalation reaction. Both types of organolithium compounds react with different electrophiles giving functionalized allylamines 7 and 10-27. Moreover, dianionic derivatives 30, 33 can be prepared directly by bromine-lithium exchange when the beta-elimination reaction of hydrogen bromide in the lithium 2-bromoallylamide is structurally hindered. Additionally, a novel type of anionic 1,3-rearrangement of a trimethylsilyl group from nitrogen to carbon is described.
Palladium(0)-catalyzed intramolecular cross coupling of bromodialkenylamines, bromoalkenylalkenamides and bromodialkenyl ethers followed by in situ [4+2] cycloaddition with suitable dienophiles gave tetrahydroisoindolines (31−73% yield), tetrahydroisoindolin-1-ones (43−51%) and hexahydrobenzo[c]furans (35−55%), and hexahydro-1H-[2]pyrindines (66−75%), respectively, each in one-pot operations.
Photoredox catalysis in the synthesis of γ- and δ-lactams from <i>N</i>-alkenyl trichloro- and dichloroacetamides
作者:Gisela Trenchs、Faïza Diaba
DOI:10.1039/d2ob00276k
日期:——
The first blue light-mediated synthesis of γ- and δ-lactams from trichloroacetamides is reported in the presence of fac-Ir(ppy)3 under an air atmosphere.