20383-28-2Relevant articles and documents
Conformational Equilibria and Torsional Barriers of the Isopropyl Groups in N,N-Diisopropylbenzamide and its Thio and Seleno Analogues
Berg, Ulf,Pettersson, Ingrid
, p. 536 - 539 (1985)
The conformations of the isopropyl groups and the barriers to conformational interconversion in N,N-diisopropylbenzamide (1), and its thio (2) and seleno (3) analogues have been studied by dynamic 1H NMR spectroscopy.In 1 only one conformation is observed
Gram-Scale Preparation of Acyl Fluorides and Their Reactions with Hindered Nucleophiles
Tryniszewski, Micha?,Barbasiewicz, Micha?
, p. 1446 - 1460 (2021/11/30)
A series of acyl fluorides was synthesized at 100 mmol scale using phase-transfer-catalyzed halogen exchange between acyl chlorides and aqueous bifluoride solution. The convenient procedure consists of vigorous stirring of the biphasic mixture at room temperature, followed by extraction and distillation. Isolated acyl fluorides (usually 7-20 g) display excellent purity and can be transformed into sterically hindered amides and esters when treated with lithium amide bases and alkoxides under mild conditions.
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
