Radical Isomerization and Cycloisomerization Initiated by H• Transfer

Abstract

Under H2 pressure, Co(II)(dmgBF2)2L2 (L = H2O, THF) generates a low concentration of an H• donor. Transfer of the H• onto an olefin gives a radical that can either (1) transfer an H• back to the metal, generating an isomerized olefin, or (2) add intramolecularly to a double bond, generating a cyclized radical. Transfer of an H• back to the metal from the cyclized radical results in a cycloisomerization. Both outcomes are favored by the low concentration of the cobalt H• donor, whereas hydrogenation and cyclohydrogenation are more likely with other catalysts (when the concentration of the H• donor is high).

Visible‐Light Controlled Divergent Catalysis Using a Bench‐Stable Cobalt(I) Hydride Complex

“…No conversion was observed in the dark without pinacolborane. Although alkene isomerisation has been reported with a wide array of metal catalysts including non‐noble metal examples with nickel or cobalt, we believed that this method compares well, requiring no additional co‐catalysts, ligands or bases . It is noteworthy that few existing alkene isomerisation methods are reported to isomerise this particular electron‐deficient substrate …”

“…Here we observed formation of hydrogen gas at the start of the reaction as well as a new signal by 11 B NMR. Cognizant of work by Norton and Shenvi on cobalt‐hydride mediated H . addition to alkenes, we trialled two substrates which we believed should undergo cycloisomerisation or radical ring opening if this was the mechanistic pathway (Scheme a and b).…”

Mn-, Fe-, and Co-Catalyzed Radical Hydrofunctionalizations of Olefins

“…399 While paying particular attention to factors which affect the outcome of a given TM HAT reaction, the authors also demonstrate the synthetic utility of this catalytic system (Figure 157). …”

Nanocrystals of halide perovskite: Synthesis, properties, and applications

“…To date, numerous researches on A site (FA + ) or B site (Bi 3 + , Mn 2 + , Zn 2 + , Sn 2 + , Cd 2 + , etc.) doped CsPbX 3 NCs were reported [86][87][88][89][90][91][92][93] . Kovalenko and co-workers [92] synthesized FAPbI 3 and FA 0.1 Cs 0.9 PbI 3 NCs which exhibited stable and highly efficient near-IR (780 nm) and red emissions (680 nm), respectively.…”

“…Following this work, several other studies were conducted in fabricating IP NCs-based LEDs [94][95][96][97][98][99][100] . Usually, the practical applications of the CsPbX 3 NCs exhibited poor thermal stability, which was associated with the intrinsically low formation energies of perovskite lattices [88,99,100] . Therefore, enhancing the formation energies of perovskite lattices of CsPbX 3 NCs held great promise in improving their poor thermal stability.…”