Mechanistic Study of Copper-Catalyzed C-H Hydroxylation/C-S Coupling by ESI-HR MS and DFT Calculations

Abstract

The reaction mechanism of Cu-catalyzed C-H hydroxylation/C-S coupling was studied using electrospray ionization high resolution mass spectrometry (ESI-HR MS) and density functional theory calculations (DFT). Notably, a series of CuI and CuIII complexes were observed as key intermediates and identified using ESI-HR MS. Furthermore, a catalyst cycle involving proton abstraction/oxidative addition/reductive elimination was proposed. This study is important and valuable with respect to C-H functionalization.

Histological Structure of the Kidney in the Iraqi Weasel, Small Asian Mangoose, (Herpestes Javanicus ) (E.Geoffroy Saint.Hilaire,1818)

“…2,7] and similar to the data indicated by [1] in jerboa and by [7] in dogs, their quantity was less in the superficial region of the cortical labyrinth than that of the of mid-cortical and juxtamedullary regions[ Fig.2,6]. The study of [19] in the kidney of the Bactrian camel recorded that renal corpuscles were absent below the capsule in the range of 1000 to 1500 μm while in the current work we observed some of the renal corpuscles are present directly below the capsule in the hilar region [ Fig. 1B].…”

“…Numerous sections of thin segments of Henle's loops were seen in the inner medulla zone of the kidney and this indicated that there were many nephrons with long loops are present in the kidney of a weasel which were a prerequisite for the production more concentrated urine in the arid and semi-arid environments. A similar observation was recorded by [13] in long-eared hedgehogs and by [19] in Bactrian camel. The thick segments of the loop of Henle had clear circular lumina, lined by one layer of low cuboidal cells [ Fig.8] which was similar to that recorded by [17] in Marwari sheep and by [3] in albino rats.…”

“…The lateral margin of the outer medullary tissue extended into the pelvic cavity to form a secondary pyramid with a specialized fornix extend deeply between the outer medulla zone and cortex [ Fig 3,4]. In Bactrian camel, [19] reported that the secondary renal pyramid in kidney lateral edge was particularly obvious. The medullary rays invade about two thirds of the cortical tissue and none reach to the capsule surface [Fig2,6], as in our study [5] reported that the medullary rays project to the outer cortex region but not extend to the capsule surface in the kidney of West Indian Manatee.…”

“…The corticomedullary junction is characterized by the presence of conspicuous arcuate vessels [arteries and veins] [Fig.4,5,6]. In Bactrian camel, [19] found that vascular bundles of vasa recta distributed in alternative pattern with the uriniferous tubules bundles in the outer medullary zone and their width was nearly equal to that of bundle while in the current work these bundles appear small or medium in size and all them were smaller than the uriniferous tubules bundles, and this suggests that kidney in weasel may less efficient in concentrate urine than kidney in Bactrian camel. Similar to previous studies achieved in many mammalian species [1,2,17,140], the transverse sections showed that the Parenchymal substance of kidney consisted of nephrons which are formed the structural units of the kidney and each of them constituted from renal corpuscle and renal tubule that composed of a proximal and distal convoluted tubule, and a loop of Henle which connected between the straight portions of them.…”

Endothelin-1 in portal hypertension: The intricate role of hepatic stellate cells

“…71 Another study by the same group revealed that Sal B is capable to inhibit ET-1 and thereby reduces the contraction of primary rat HSCs through its suppressive effects on myosin light chain 2 phosphorylation in HSCs. 72…”