scholarly journals Direct enantioseparation of axially chiral 1,1′-biaryl-2,2′-diols using amidine-based resolving agents

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18162-18170
Author(s):  
Koichi Kodama ◽  
Fusato Takase ◽  
Takuji Hirose

Enantioseparation of atropisomeric biphenols using a chiral amidine derived from dehydroabietic acid was reported. Only one crystallization of their mixture gave pure diastereomeric salts of biphenols from racemate.

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Claudio Bruno ◽  
Giovanni Lentini ◽  
Angelo Lovece ◽  
Maria Maddalena Cavalluzzi ◽  
Alessia Carocci ◽  
...  

An efficient microwave-assisted synthesis of(±)-mandelic acid-d5was developed. The racemic mixture was resolved by diastereomeric salt formation using 1-phenylethylamine enantiomers as resolving agents. At each step, the resolution process was checked by determining mandelic acid-d5enantiomer ee values directly on fractional crystallized diastereomeric salts by chiral capillary electrophoresis analysis. Highly enriched (−)- and (+)-mandelic acid-d5(95% and 90% ee, resp.) were obtained and their absolute configurations—RandS, respectively—were determined by correlation of the (−)-mandelic acid-d5circular dichroism spectrum to the (R)-mandelic acid one.


2010 ◽  
Vol 110 (1) ◽  
pp. 13-18 ◽  
Author(s):  
F. J. J. Leusen ◽  
H. J. Bruins Slot ◽  
J. H. Noordik ◽  
A. D. van der Haest ◽  
H. Wynberg ◽  
...  

2003 ◽  
Vol 14 (21) ◽  
pp. 3297-3300 ◽  
Author(s):  
Zhang Guangyou ◽  
Liao Yuquing ◽  
Wang Zhaohui ◽  
Hiroyuki Nohira ◽  
Takuji Hirose

Author(s):  
Primali Navaratne ◽  
Jenny Wilkerson ◽  
Kavindri Ranasinghe ◽  
Evgeniya Semenova ◽  
Lance McMahon ◽  
...  

<div> <div> <div> <p>Phytocannabinoids, molecules isolated from cannabis, are gaining attention as promising leads in modern medicine, including pain management. Considering the urgent need for combating the opioid crisis, new directions for the design of cannabinoid-inspired analgesics are of immediate interest. In this regard, we have hypothesized that axially-chiral-cannabinols (ax-CBNs), unnatural (and unknown) isomers of cannabinol (CBN) may be valuable scaffolds for cannabinoid-inspired drug discovery. There are multiple reasons for thinking this: (a) ax-CBNs would have ground-state three-dimensionality akin to THC, a key bioactive component of cannabis, (b) ax-CBNs at their core structure are biaryl molecules, generally attractive platforms for pharmaceutical development due to their ease of functionalization and stability, and (c) atropisomerism with respect to phytocannabinoids is unexplored “chemical space.” Herein we report a scalable total synthesis of ax-CBNs, examine physical properties experimentally and computationally, and provide preliminary behavioral and analgesic analysis of the novel scaffolds. </p> </div> </div> </div>


2020 ◽  
Author(s):  
Ziqing Zuo ◽  
Raphael Kim ◽  
Donald Watson

<div><p>We report an asymmetric Ullmann-type homocoupling of <i>ortho-</i>(iodo)arylphosphine oxides and <i>ortho</i>-(iodo)arylphosphonates that results in highly enantioenriched axially chiral bisphosphine oxides and bisphosphonates in good yields and excellent enantioselectivities. These products are readily converted to enantioenriched biaryl bisphosphines without need for chiral auxiliaries or optical resolution. This process provides a straightforward and practical route for the development of previously uninvestigated atroposelective biaryl bisphosphine ligands.</p></div>


2004 ◽  
Vol 39 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Keith B. Tierney ◽  
Eric Stockner ◽  
Christopher J. Kennedy

Abstract This study explored the effects of a sublethal 96-h dehydroabietic acid (DHAA) exposure on aspects of the immune system of juvenile coho salmon under varying temperature conditions. Coho were exposed to DHAA concentrations below the determined LC50 value of 0.94 mg/L (95% confidence limits of 0.81 to 1.24 mg/L) for 96 h at either their acclimation temperature (8 or 18°C), or during an acute warm-shock (8 to 18°C) or cold-shock (18 to 8°C). Acclimation temperature alone significantly affected hematocrit (Hct), neutrophil respiratory burst activity (RBA) and leucocyte proportions. With temperature-shock, leucocrit (Lct), RBA and leucocyte proportions were altered. All parameters were affected by DHAA exposure, but not always in a dose-dependent manner. Across groups, DHAA caused Hct, lysozyme, thrombocyte, neutrophil and monocyte proportions to increase, and Lct, RBA and lymphocyte proportions to decrease. DHAA-temperature interactions resulted in the exacerbation of DHAA-induced effects. Exposure temperature had the most significant effect on the susceptibility of coho to Aeromonas salmonicida; fish were more susceptible at cold temperatures and when subjected to a temperature-shock compared to their respective controls. DHAA exposure modulated the response of temperature-shocked fish to this pathogen.


2012 ◽  
Vol 10 (2) ◽  
pp. 102-110 ◽  
Author(s):  
Cui Yan-Jie ◽  
Rao Xiao-Ping ◽  
Shang Shi-Bin ◽  
Song Jie ◽  
Gao Yan-Qing

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