scholarly journals Efficient Access to 2‐Pyrones via Carbene‐Catalyzed Oxidative [3+3] Reactions between Enals and Nitrogen Ylides

2019 ◽  
Vol 8 (7) ◽  
pp. 1067-1070 ◽  
Author(s):  
Pengcheng Zheng ◽  
Chengcheng Li ◽  
Chengli Mou ◽  
Dingwu Pan ◽  
Shuquan Wu ◽  
...  
Keyword(s):  
Efficient Access ◽  
Nitrogen Ylides

Sequential C-Selective Difluoromethylation/Pd-Catalyzed Decarboxylative Protonation: An Efficient Access to Tertiary Difluoromethylated Scaffolds

2019 ◽  
Author(s):  
Nicolas Duchemin ◽  
Roberto Buccafusca ◽  
Marc Daumas ◽  
Vincent Ferey ◽  
Stellios Arseniyadis
Keyword(s):  
Drug Development ◽  
Late Stage ◽  
Efficient Access ◽  
Palladium Catalyzed ◽  
General Method

We report here a general method that allows a highly straightforward access to tertiary difluoromethylated compounds. The strategy relies on a two-step sequence featuring a C-selective electrophilic difluoromethylation and an unprecedented palladium-catalyzed decarboxylative protonation. Considering the generality of the method and the attractive properties offered by the difluoromethyl group, this approach provides a valuable tool for late-stage functionalization and drug development.<br>

Electrochemical Oxidative Esterification of Thiophenols: Efficient Access to Sulfinic Esters

2020 ◽  
Vol 17 (7) ◽  
pp. 540-547
Author(s):  
Chun-Hui Yang ◽  
Cheng Wu ◽  
Jun-Ming Zhang ◽  
Xiang-Zhang Tao ◽  
Jun Xu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Efficient Method ◽  
High Efficiency ◽  
Building Blocks ◽  
Constant Current ◽  
Good Efficiency ◽  
Oxidative Esterification ◽  
Efficient Access ◽  
New Applications ◽  
Sulfinic Esters

Background: The sulfinic esters are important and useful building blocks in organic synthesis. Objective: The aim of this study was to develop a simple and efficient method for the synthesis of sulfinic esters. Materials and Methods: Constant current electrolysis from thiols and alcohols was selected as the method for the synthesis of sulfinic esters. Results and Discussion: A novel electrochemical method for the synthesis of sulfinic esters from thiophenols and alcohols has been developed. Up to 27 examples of sulfinic esters have been synthesized using the current methods. This protocol shows good functional group tolerance as well as high efficiency. In addition, this protocol can be easily scaled up with good efficiency. Notably, heterocycle-containing substrates, including pyridine, thiophene, and benzothiazole, gave the desired products in good yields. A plausible reaction mechanism is proposed. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. It is considered that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in the future.

scholarly journals The impact of COVID-19 related national lockdown on ophthalmic emergency in Italy: A multicenter study

2021 ◽  
pp. 112067212110280
Author(s):  
Maria L Salvetat ◽  
Carlo Salati ◽  
Patrizia Busatto ◽  
Marco Zeppieri
Keyword(s):  
Gender Bias ◽  
Tertiary Care ◽  
Lower Number ◽  
Electronic Records ◽  
Chi Square ◽  
Efficient Access ◽  
Chi Square Test ◽  
Unpaired Student ◽  
The Impact ◽  
Wet Amd

Purpose: To assess ocular pathologies admitted to Italian Emergency Eye Departments (EEDs) during the COVID-19 pandemic national lockdown in 2020 in comparison with the same period in 2019. Methods: Electronic records of all patients presenting at EEDs of two tertiary-care Eye Centers during the COVID-19 national lockdown in Italy (March 10–May 3, 2020) were compared with the equivalent period in 2019. Main outcomes were patient age, gender, and diagnoses. Statistical analysis included unpaired Student t-tests, Poisson regression, and chi-square test. Results: Overall EED visits significantly decreased by 54.1% during the 2020 lockdown compared to 2019 (851 vs 1854, p < 0.001). During lockdown, patients showed comparable mean age (52.8 years in 2020 vs 53.3 years in 2019, p = 0.52) and significant male gender bias (61.1% in 2020 vs 55.8% in 2019, p < 0.0001). The most frequent pathologies were eye inflammations, trauma-related incidents, and spontaneous acute vitreous detachment. Patients with inflammation, headache/hemicrania, and spontaneous subconjunctival hemorrhages were significantly less, whereas those with trauma-related diagnoses were significantly higher during the lockdown as compared with 2019 ( p < 0.05). The proportion of non-urgent visits decreased from 17% in 2019 to 8% in 2020 ( p < 0.001). Conclusions: During the 2020 lockdown, there was a significant reduction of accesses to EED, especially for non-urgent pathologies. Potentially visual function threatening conditions, such as trauma-related pathologies, retinal detachment or ruptures, and wet AMD, showed lower number of cases but higher or stable proportion relative to the total caseload, suggesting a correct and efficient access to ophthalmic health care during the pandemic period.

scholarly journals Stereoselective Tandem Iridium-Catalyzed Alkene Isomerization-Cope Rearrangement of ω-diene Epoxides: Efficient Access to Acyclic 1,6-Dicarbonyl Compounds

2021 ◽  
Author(s):  
Rahul Suresh ◽  
Itai Massad ◽  
Ilan Marek
Keyword(s):  
Bond Cleavage ◽  
Cope Rearrangement ◽  
Dicarbonyl Compounds ◽  
Alkene Isomerization ◽  
Efficient Access

The Cope rearrangement of 2,3-divinyloxiranes, a rare example of epoxide C-C bond cleavage, results in 4,5-dihydrooxepines which are amenable to hydrolysis, furnishing 1,6-dicarbonyl compounds containing two contiguous stereocenters at the 3- and 4- positions. We employ...

Cu‐Catalyzed Oxidative C‐C Cleavage of Carbohydrates: An Efficient Access to Quinazolinone Scaffolds

2021 ◽  
Author(s):  
Abigail Philips ◽  
Dineshkumar Raja ◽  
Ajithkumar Arumugam ◽  
Wei-Yu Lin ◽  
Gopal Chandru Senadi
Keyword(s):  
Efficient Access
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