56139-59-4Relevant articles and documents
From Ring-Expansion to Ring-Contraction: Synthesis of γ-Lactones from Cyclobutanols and Relative Stability of Five- and Six-Membered Endoperoxides toward Organic Bases
Ferrié, Laurent,Jamey, Nicolas
, (2022/04/07)
Cyclobutanols undergo ring expansion with molecular oxygen in the presence of Co(acac)2 to afford 1,2-dioxane-hemiperoxyketals. In the course of acylation, we observed that endoperoxides rearranged into ?-lactone in the presence of triethylamine. Thus, a generalization of this ring contraction through a Kornblum DeLaMare rearrangement is here reported. Application of this transformation to monosubstituted 1,2-dioxane derivatives also led to 1,4-ketoaldehydes, in proportions depending on the nature of the substituent. These same conditions applied to five-membered dioxolane analogues led to fragmentation instead, through a retro-aldol type process. This study emphasizes the difference of stability of 1,2-dioxane and 1,2-dioxolane against organic bases, 1,2-dioxolanes having proved to be particularly reactive whereas 1,2-dioxanes showed a relative tolerance under these conditions.
VISIBLE-LIGHT MEDIATED ORGANOPHOTOREDOX CATALYTIC DEUTERATION OF AROMATIC AND ALIPHATIC ALDEHYDES
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Paragraph 0067-0068, (2021/06/22)
Described are methods for preparing a deuterated aldehyde using with a photocatalyst and a hydrogen atom transfer agent in a H2O free solvent comprising D2O and an organic solvent under an inert gas. The methods may be used to convert a wide variety of aldehydes (e.g., aryl, alkyl, or alkenyl aldehydes) to C-1 deuterated aldehydes under mild reaction conditions.
Atroposelective Synthesis of Axially Chiral N-Arylpyrroles by Chiral-at-Rhodium Catalysis
Chen, Shuming,Han, Feng,Houk, K. N.,Ivlev, Sergei,Meggers, Eric,Xie, Xiulan,Ye, Chen-Xi
supporting information, p. 13552 - 13556 (2020/06/05)
A transformation of fluxional into configurationally stable axially chiral N-arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral-at-metal rhodium Lewis acid. Specifically, N-arylpyrroles were alkylated with N-acryloyl-1H-pyrazole electrophiles in up to 93 percent yield and with up to >99.5 percent ee, and follow-up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.