Ppm Cu Catalyst Enables -Alkylation Followed by C-H Cyclization To Synthesize Substituted Oxindoles.

In this paper, we established highly efficient Cu-catalyzed tandem -alkylation C-H cyclization of α-bromocarbonyls and methacrylamides to produce substituted oxindoles. The maximum turnover number was up to 48 000 with reasonable yield. Although the catalyst loadings were very low, the reaction was not involving radical chain reaction.

A highly efficient Cu catalyst system for the radical reactions of α-bromocarbonyls.

In this communication, we established highly efficient Cu-catalyzed ARGET-ATRS (atom-transfer radical substitution) of alpha-bromocarbonyls with styrenes to produce tert-alkylated styrenes. The maximum TON was up to 12 000. Hünig's base was very important to regenerate active Cu.

Exchanging Alkyl Groups through Unstrained C-C Bond Cleavage in the Presence of a Copper Catalyst.

Although numerous reports exist on strained C-C bond cleavage reactions in aryl substitutions, the cleavage methodology for unstrained C-C bonds in alkylation reactions has not yet been established. We found that unstrained allylic C-C bonds can be cleaved using α-radicals to form C(sp )-C(sp ) bonds in the presence of a copper catalyst. In this reaction, the property of leaving and loading radicals is very important for radical fragmentations.

A facile formal [2+1] cycloaddition of styrenes with alpha-bromocarbonyls catalyzed by copper: efficient synthesis of donor-acceptor cyclopropanes.

Reactions of 2-bromoesters and styrenes underwent a [2+1] cycloaddition reaction, i.e., cyclopropanation, to produce donor-acceptor (D-A) cyclopropanes through a radical addition-ring closure process.

A Copper-Catalyzed Formal [3 + 2]-Cycloaddition for the Synthesis of All Different Aryl-Substituted Furans and Thiophenes.

A highly efficient formal [3 + 2]-cycloaddition was established using a copper catalyst. The resulting dihydrofurans were subjected to oxidation followed by arylations to produce tetraarylfurans. In addition, the dihydrofuran can be converted to diaryldihydrothiophene by using Lawesson's reagent.

An efficient generation of a functionalized tertiary-alkyl radical for copper-catalyzed tertiary-alkylative Mizoroki-Heck type reaction.

α-Halocarbonyl compounds undergo β-hydrogen elimination to give conjugated olefins in the presence of a transition-metal catalyst. However, a copper/triamine catalyst system can induce the alkylative Mizoroki–Heck reaction of styrenes with tertiary-alkyl halides possessing a withdrawing group under very mild conditions. This reaction provides an efficient synthetic methodology for tertiary-alkylated styrenes.