Straightforward synthesis of chiral non-racemic α-boryl isocyanides

2021 ◽  
Author(s):  
Francesco Fini ◽  
Alessandro Zanni ◽  
Maria Luisa Introvigne ◽  
Mattia Stucchi ◽  
Emilia Caselli ◽  
...  
Keyword(s):  
Multicomponent Reaction ◽  
Bioactive Molecules ◽  
Synthetic Sequence ◽  
Key Steps

A straightforward concise synthesis of chiral non-racemic aliphatic α-boryl isocyanides, relay intermediates for boron-based bioactive molecules by using multicomponent reaction, is presented. The short synthetic sequence comprises as key steps...

scholarly journals Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

2020 ◽  
Vol 16 ◽  
pp. 738-755
Author(s):  
Valerian Dragutan ◽  
Ileana Dragutan ◽  
Albert Demonceau ◽  
Lionel Delaude
Keyword(s):  
Therapeutic Agents ◽  
Ruthenium Catalysts ◽  
Diels Alder ◽  
Bioactive Molecules ◽  
Enyne Metathesis ◽  
Organic Transformations ◽  
Chemically Modified ◽  
Key Steps ◽  
Powerful Strategy

This account surveys the current progress on the application of intra- and intermolecular enyne metathesis as main key steps in the synthesis of challenging structural motifs and stereochemistries found in bioactive compounds. Special emphasis is placed on ruthenium catalysts as promoters of enyne metathesis to build the desired 1,3-dienic units. The advantageous association of this approach with name reactions like Grignard, Wittig, Diels–Alder, Suzuki–Miyaura, Heck cross-coupling, etc. is illustrated. Examples unveil the generality of such tandem reactions in providing not only the intricate structures of known, in vivo effective substances but also for designing chemically modified analogs as valid alternatives for further therapeutic agents.

scholarly journals Total Synthesis of Surinamensinols A and B

SynOpen ◽  
2020 ◽  
Vol 04 (04) ◽  
pp. 84-88
Author(s):  
Ahmed Al-Harrasi ◽  
Satya Kumar Avula ◽  
Biswanath Das ◽  
Rene Csuk ◽  
Ahmed Al-Rawahi
Keyword(s):  
Total Synthesis ◽  
Allyl Alcohol ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Ethyl Lactate ◽  
Naturally Occurring ◽  
Cross Coupling Reaction ◽  
Synthetic Sequence ◽  
Key Steps ◽  
Single Approach

AbstractAn efficient total synthesis of the naturally occurring anti-inflammatory and antitumour 8-O-4′-neolignans, surinamensinols A and B, has been accomplished from commercially available allyl alcohol and (S)-ethyl lactate. The synthetic sequence involves a palladium-catalysed Suzuki–Miyaura cross-coupling reaction followed by a chiral Mitsunobu­ reaction as the key steps. This is the first report of the simultaneous stereoselective total synthesis of surinamensinols A and B through a single approach involving only six steps.

Synthesis of 3′,7′-anhydrooctose nucleosides related to the ezomycins and the octosyl acids

1981 ◽  
Vol 59 (5) ◽  
pp. 878-888 ◽  
Author(s):  
Kwan Soo Kim ◽  
Walter A. Szarek
Keyword(s):  
Carboxylic Acid ◽  
Wittig Reaction ◽  
Chain Extension ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Reaction Conversion ◽  
Synthetic Sequence ◽  
A Chain ◽  
Key Steps ◽  
Acid Function

Several novel 3′,7′-anhydrooctose nucleosides, including a 3′,7′-anhydroocturonic acid nucleoside, namely l-(3,7-anhydro-5,6-dideoxy-β-D-allo-octofuranosyluronic acid)-3-methyluracil (40), have been synthesized. The synthetic sequence leading to 40 consists of three key steps: preparation of an octose nucleoside by a chain extension of an uridine derivative using a Wittig reaction, conversion of the octose nucleoside into a bicyclic-octose nucleoside by an intramolecular cyclization, and elaboration of a carboxylic acid function at the C-8′ position of the bicyclic-octose nucleoside. The structures of the 3′,7′-anhydrooctose nucleosides have been established by their uv, 1Hmr, 13Cmr, and mass spectral data.

scholarly journals Carbene-Catalyzed Atroposelective Synthesis of Axially Chiral Styrenes Bearing Acyclic Alkenes

2021 ◽  
Author(s):  
Jia-Lei Yan ◽  
Rakesh Maiti ◽  
Shi-Chao Ren ◽  
Weiyi Tian ◽  
Tingting Li ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Rotational Barrier ◽  
Bioactive Molecules ◽  
Carboxylic Ester ◽  
Aryl Ring ◽  
Axially Chiral ◽  
Sulfinic Acids ◽  
Set Up ◽  
Key Steps ◽  
Asymmetric Solution

Abstract Axially chiral styrenes bearing a chiral axis between a sterically non-congested acyclic alkene and an aryl ring are difficult to prepare due to low rotational barrier of the axis. Disclosed here is an N-heterocyclic carbene (NHC) catalytic asymmetric solution to this problem. Our reaction involves ynals, sulfinic acids, and phenols as the substrates with an NHC as the catalyst. Key steps involve selective 1,4-addition of sulfinic anion to acetylenic acylazolium intermediate and sequential E-selective protonation to set up the chiral axis. Our reaction affords axially chiral styrenes bearing a chiral axis as the product with up to >99:1 e.r., >20:1 E/Z selectivity, and excellent yields. The sulfone and carboxylic ester moieties in our styrene products are common moieties in bioactive molecules and asymmetric catalysis.

scholarly journals Carbene-catalyzed atroposelective synthesis of axially chiral styrenes

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Jia-Lei Yan ◽  
Rakesh Maiti ◽  
Shi-Chao Ren ◽  
Weiyi Tian ◽  
Tingting Li ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Rotational Barrier ◽  
Bioactive Molecules ◽  
Carboxylic Ester ◽  
Aryl Ring ◽  
Axially Chiral ◽  
Sulfinic Acids ◽  
Set Up ◽  
Key Steps ◽  
Asymmetric Solution

AbstractAxially chiral styrenes bearing a chiral axis between a sterically non-congested acyclic alkene and an aryl ring are difficult to prepare due to low rotational barrier of the axis. Disclosed here is an N-heterocyclic carbene (NHC) catalytic asymmetric solution to this problem. Our reaction involves ynals, sulfinic acids, and phenols as the substrates with an NHC as the catalyst. Key steps involve selective 1,4-addition of sulfinic anion to acetylenic acylazolium intermediate and sequential E-selective protonation to set up the chiral axis. Our reaction affords axially chiral styrenes bearing a chiral axis as the product with up to > 99:1 e.r., > 20:1 E/Z selectivity, and excellent yields. The sulfone and carboxylic ester moieties in our styrene products are common moieties in bioactive molecules and asymmetric catalysis.

scholarly journals A One-Pot Process for the Synthesis of Alkyne-3-tretrazolyl-tetrazolo [1,5-a] Quinolines

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 42 ◽  
Author(s):  
Sandra C. Ramírez-López ◽  
M.V. Basavanag Unnamatla ◽  
Rocío Gámez-Montaño
Keyword(s):  
Multicomponent Reaction ◽  
Medicinal Chemistry ◽  
Bioactive Molecules ◽  
Efficient Synthesis ◽  
One Pot ◽  
One Pot Synthesis ◽  
The One ◽  
Preparation And Evaluation ◽  
Privileged Scaffolds

An efficient synthesis of alkyne-3-tetrazolyl-tetrazolo[1,5-a] quinolones via a one-pot isocyanide-based multicomponent reaction (IMCR) process: I-MCR Ugi-azide/SNAr/ring-chain azido tautomerization was performed under eco-friendly conditions. We report the one-pot synthesis of tris-heterocycles containing a tetrazolo[1,5-a] quinoline connected to a 1,5-disubstituted-tetrazole (1,5-DS-T). The synthesis of these compounds is of great interest in synthetic and medicinal chemistry because these heterocycles are considered privileged scaffolds and their preparation and evaluation may lead to the discovery of novel bioactive molecules.

Total syntheses of the sesquiterpenoids (±)-axamide-1, (±)-axisonitrile-1, and the corresponding C-10 epimers

1986 ◽  
Vol 64 (12) ◽  
pp. 2475-2476 ◽  
Author(s):  
Edward Piers ◽  
Bik Wah Anissa Yeung
Keyword(s):  
Conjugate Addition ◽  
Total Syntheses ◽  
Synthetic Sequence ◽  
Key Steps

Total syntheses of (±)-axamide-1 (1), (±)-axisonitrile-1 (2), and the corresponding C-10 epimers 16 and 17 are described. The key steps of the synthetic sequence involve methylenecyclohexane annulation of 2-methyl-2-cyclopenten-1-one and TiCl4-catalyzed conjugate addition of 3-methyl-1,1-bis(trimethylsiloxy)-1-butene to the bicyclic enone 8.

scholarly journals Manipulating a Multicomponent Reaction: A Straightforward Approach to Chromenopyrazole Hybrid Scaffolds

Synthesis ◽  
2017 ◽  
Vol 49 (16) ◽  
pp. 3619-3632 ◽  
Author(s):  
Constantinos Neochoritis ◽  
Paraskevi Kasapidou ◽  
Tryfon Zarganes-Tzitzikas ◽  
Constantinos Tsoleridis ◽  
Julia Stephanidou-Stephanatou
Keyword(s):  
Multicomponent Reaction ◽  
13C Nmr ◽  
Chemical Shifts ◽  
Bioactive Molecules ◽  
Easy Access ◽  
Nmr Analysis ◽  
1H And 13C Nmr ◽  
13C Nmr Chemical Shifts ◽  
Hybrid Scaffolds ◽  
Straightforward Approach

An easy access to hybrid bioactive molecules, such as the chromenopyrazoles, is described based on the three-component reactions of 3-formylchromones, arylhydrazines, and acetylenedicarboxylates. By manipulating the reaction, four different scaffolds can be derived in an easy, versatile, and robust fashion. To underscore the potential, generality, and diversity that can be generated, representative libraries of each scaffold were synthesized. Moreover, a comprehensive NMR analysis with full assignment of all 1H and 13C NMR chemical shifts has been performed.

Reflections on the Cognitive Interviewing Reporting Framework

Methodology ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Gordon Willis ◽  
Hennie Boeije
Keyword(s):  
Research Design ◽  
Cognitive Testing ◽  
Level Of Detail ◽  
Cognitive Interviewing ◽  
Research Groups ◽  
Research Project ◽  
Reporting Framework ◽  
Full Explanation ◽  
Key Steps

Based on the experiences of three research groups using and evaluating the Cognitive Interviewing Reporting Framework (CIRF), we draw conclusions about the utility of the CIRF as a guide to creating cognitive testing reports. Authors generally found the CIRF checklist to be usable, and that it led to a more complete description of key steps involved. However, despite the explicit direction by the CIRF to include a full explanation of major steps and features (e.g., research objectives and research design), the three cognitive testing reports tended to simply state what was done, without further justification. Authors varied in their judgments concerning whether the CIRF requires the appropriate level of detail. Overall, we believe that current cognitive interviewing practice will benefit from including, within cognitive testing reports, the 10 categories of information specified by the CIRF. Future use of the CIRF may serve to direct the overall research project from the start, and to further the goal of evaluation of specific cognitive interviewing procedures.

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