770-71-8Relevant articles and documents
Radical hydroxymethylation of alkyl iodides using formaldehyde as a C1 synthon
Caiger, Lewis,Constantin, Timothée,Douglas, James J.,Juliá, Fabio,Leonori, Daniele,Sheikh, Nadeem S.,Sinton, Conar
, p. 10448 - 10454 (2021/08/20)
Radical hydroxymethylation using formaldehyde as a C1 synthon is challenging due to the reversible and endothermic nature of the addition process. Here we report a strategy that couples alkyl iodide building blocks with formaldehyde through the use of photocatalysis and a phosphine additive. Halogen-atom transfer (XAT) from α-aminoalkyl radicals is leveraged to convert the iodide into the corresponding open-shell species, while its following addition to formaldehyde is rendered irreversible by trapping the transient O-radical with PPh3. This event delivers a phosphoranyl radical that re-generates the alkyl radical and provides the hydroxymethylated product.
Development of effective bidentate diphosphine ligands of ruthenium catalysts toward practical hydrogenation of carboxylic acids
Saito, Susumu,Wen, Ke,Yoshioka, Shota
, p. 1510 - 1524 (2021/06/18)
Hydrogenation of carboxylic acids (CAs) to alcohols represents one of the most ideal reduction methods for utilizing abundant CAs as alternative carbon and energy sources. However, systematic studies on the effects of metal-to-ligand relationships on the catalytic activity of metal complex catalysts are scarce. We previously demonstrated a rational methodology for CA hydrogenation, in which CA-derived cationic metal carboxylate [(PP)M(OCOR)]+ (M = Ru and Re; P = one P coordination) served as the catalyst prototype for CA self-induced CA hydrogenation. Herein, we report systematic trial- and-error studies on how we could achieve higher catalytic activity by modifying the structure of bidentate diphosphine (PP) ligands of molecular Ru catalysts. Carbon chains connecting two P atoms as well as Ar groups substituted on the P atoms of PP ligands were intensively varied, and the induction of active Ru catalysts from precatalyst Ru(acac)3 was surveyed extensively. As a result, the activity and durability of the (PP)Ru catalyst substantially increased compared to those of other molecular Ru catalyst systems, including our original Ru catalysts. The results validate our approach for improving the catalyst performance, which would benefit further advancement of CA self-induced CA hydrogenation.
A General Method for Photocatalytic Decarboxylative Hydroxylation of Carboxylic Acids
Khan, Shah Nawaz,Zaman, Muhammad Kashif,Li, Ruining,Sun, Zhankui
, p. 5019 - 5026 (2020/05/01)
A general and practical method for decarboxylative hydroxylation of carboxylic acids was developed through visible light-induced photocatalysis using molecular oxygen as the green oxidant. The addition of NaBH4 to in situ reduce the unstable peroxyl radical intermediate much broadened the substrate scope. Different sp3 carbon-bearing carboxylic acids were successfully employed as substrates, including phenylacetic acid-type substrates, as well as aliphatic carboxylic acids. This transformation worked smoothly on primary, secondary, and tertiary carboxylic acids.