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1.
Org Lett ; 25(18): 3216-3221, 2023 May 12.
Article in English | MEDLINE | ID: mdl-37130365

ABSTRACT

Herein, we report a highly modular strategy to access spirocyclic scaffolds from abundant starting materials, i.e., cyclic ketones and α-amino or oxamic acids. The sequence proceeds through a straightforward Knoevenagel condensation, followed by a domino Giese-type reaction/base-mediated cyclization process, to deliver a broad scope of polar spirocyclic scaffolds in good to excellent yields. The products can be readily diversified, thus increasing the versatility of our method to gain rapid access to libraries of potential druglike molecules.

2.
Angew Chem Int Ed Engl ; 61(50): e202204624, 2022 12 12.
Article in English | MEDLINE | ID: mdl-35570718

ABSTRACT

The structure of in situ generated chiral aryl-λ3 -iodanes obtained under oxidative reaction conditions was not yet observable with experimental techniques and their proposed structures are purely based on DFT calculations. Herein, we establish vibrational circular dichroism (VCD) spectroscopy as an experimental technique to verify DFT-calculated chiral iodane structures. Based on a chiral triazole-substituted iodoarene catalyst, we were able to elucidate a yet undescribed cationic chiral iodane as the most populated intermediate under oxidative conditions with a significant intramolecular N-I-interaction and no significant interactions with tosylate or m-chlorobenzoic acid as potential anionic ligands. Instead, aggregation of these substrates was found, which resulted in the formation of a non-coordinating anionic hydrogen bonded complex. The importance of VCD as a crucial experimental observable is further highlighted by the fact that our initial structural proposal, that was purely based on DFT calculations, could be falsified.


Subject(s)
Iodine , Circular Dichroism , Stereoisomerism , Ligands , Iodides
3.
Chem Commun (Camb) ; 57(70): 8822-8825, 2021 Sep 11.
Article in English | MEDLINE | ID: mdl-34382967

ABSTRACT

A catalytic highly enantioselective synthesis of spirooxazolines is presented. Starting from readily available 2-naphthol-substituted benzamides and using catalytic amounts of a chiral triazole-substituted iodoarene catalyst, a variety of spirooxazolines can be isolated through an enantioselective oxidative dearomatization in up to 92% yield and 97% ee. The further synthetic utility of the optically enriched spirooxazolines was examined providing a corresponding 2-naphthalenole and an oxepin.

4.
Pharm Pract (Granada) ; 19(2): 2306, 2021.
Article in English | MEDLINE | ID: mdl-34221198

ABSTRACT

OBJECTIVE: To evaluate the knowledge, believes, psychological and behavioural impact of COVID-19 on the general population in the Middle East, exploring how it impacted public lives. METHODS: A descriptive cross-sectional online survey was sent to a convenience sample in the Middle East through social media (Facebook and WhatsApp) between 16th of June and 30th of June 2020. The questionnaire was designed to collect the demographic, participant's source of information regarding COVID-19, knowledge and believes about COVID-19, the psychological consequences of COVID-19, impact of COVID-19 on participant's behaviour. The final version of the questionnaire was further tested for content validity by experts in the field. RESULTS: A total of 2,061 participants completed the survey, with the majority being females (n=1394, 67.6%), from urban areas (n=1896, 92%) and the majority were from countries of The Levant (n=1199, 58.1%), followed by the Arabian Peninsula (n=392, 19.1%), Iraq (n=300, 14.6%) and Egypt (n=138, 6.7%). Few participants (3.0%) reported to have been infected and many (n=1847, 89.6%) were committed to quarantine at home. Social media platforms were the most common sources of information (41.2%). Many (63%) believed that COVID-19 is a biological weapon and were afraid of visiting crowded places (85%). The majority avoided public facilities (86.9%) such as prayer places and believed that the news about COVID-19 made them anxious (49.5%).

5.
Org Lett ; 23(13): 5076-5080, 2021 Jul 02.
Article in English | MEDLINE | ID: mdl-34138574

ABSTRACT

This study presents an enantioselective oxidative cyclization of N-allyl carboxamides via a chiral triazole-substituted iodoarene catalyst. The method allows the synthesis of highly enantioenriched oxazolines and oxazines, with yields of up to 94% and enantioselectivities of up to 98% ee. Quaternary stereocenters can be constructed and, besides N-allyl amides, the corresponding thioamides and imideamides are well tolerated as substrates, giving rise to a plethora of chiral 5-membered N-heterocycles. By applying a multitude of further functionalizations, we finally demonstrate the high value of the observed chiral heterocycles as strategic intermediates for the synthesis of other enantioenriched target structures.

6.
Pharm. pract. (Granada, Internet) ; 19(2)apr.- jun. 2021. tab
Article in English | IBECS | ID: ibc-225532

ABSTRACT

Objective: To evaluate the knowledge, believes, psychological and behavioural impact of COVID-19 on the general population in the Middle East, exploring how it impacted public lives. Methods: A descriptive cross-sectional online survey was sent to a convenience sample in the Middle East through social media (Facebook and WhatsApp) between 16th of June and 30th of June 2020. The questionnaire was designed to collect the demographic, participant’s source of information regarding COVID-19, knowledge and believes about COVID-19, the psychological consequences of COVID-19, impact of COVID-19 on participant’s behaviour. The final version of the questionnaire was further tested for content validity by experts in the field. Results: A total of 2,061 participants completed the survey, with the majority being females (n=1394, 67.6%), from urban areas (n=1896, 92%) and the majority were from countries of The Levant (n=1199, 58.1%), followed by the Arabian Peninsula (n=392, 19.1%), Iraq (n=300, 14.6%) and Egypt (n=138, 6.7%). Few participants (3.0%) reported to have been infected and many (n=1847, 89.6%) were committed to quarantine at home. Social media platforms were the most common sources of information (41.2%). Many (63%) believed that COVID-19 is a biological weapon and were afraid of visiting crowded places (85%). The majority avoided public facilities (86.9%) such as prayer places and believed that the news about COVID-19 made them anxious (49.5%) (AU)


Subject(s)
Humans , Male , Female , Adult , Health Knowledge, Attitudes, Practice , Coronavirus Infections , Pandemics , Attitude to Health , Cross-Sectional Studies , Surveys and Questionnaires , Socioeconomic Factors , Middle East
7.
Angew Chem Int Ed Engl ; 59(4): 1479-1484, 2020 01 20.
Article in English | MEDLINE | ID: mdl-31600009

ABSTRACT

A widely applicable triazole-substituted chiral aryl iodide is described as catalyst for enantioselective oxidation reactions. The introduction of a substituent in ortho-position to the iodide is key for its high reactivity and selectivity. Besides a robust and modular synthesis, the main advantage of this catalyst is the excellent performance in a plethora of mechanistically diverse enantioselective transformations, such as spirocyclizations, phenol dearomatizations, α-oxygenations, and oxidative rearrangements. DFT-calculations of in situ generated [hydroxy(tosyloxy)iodo]arene isomers give an initial rational for the observed reactivity.

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