Chemoselective reduction of tertiary amides by 1,3-diphenyldisiloxane (DPDS)

Synthesis ◽  
2021 ◽  
Author(s):  
Travis Hammerstad ◽  
Pooja V. Hegde ◽  
Kathleen J. Wang ◽  
Courtney Aldrich
Keyword(s):  
Environmental Impact ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Safety Profile ◽  
Room Temperature ◽  
Reaction Conditions ◽  
Excellent Safety Profile ◽  
Set Up ◽  
Tertiary Amides ◽  
Secondary Amides

A convenient procedure for the chemoselective reduction of tertiary amides at room temperature in the presence of air and moisture using 1,3-diphenyldisiloxane (DPDS) has been developed. The reaction conditions are tolerant of a great number of functional groups including esters, nitriles, secondary amides, carbamates, sulfoxides, sulfones, sulfonyl fluorides, halogens, aryl-nitro groups, and arylamines. The conditions reported are the mildest to date and utilize EtOAc, a preferred solvent given its excellent safety profile and lower environmental impact. The ease of set up and broad chemoselectivity make this method attractive for organic synthesis. These results further demonstrate the utility of DPDS as a selective reducing agent.

scholarly journals Sulfoximines-Assisted Rh(III)-Catalyzed C–H Activation and Intramolecular Annulation for the Synthesis of Fused Isochromeno-1,2-Benzothiazines Scaffolds under Room Temperature

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2515
Author(s):  
Bao Wang ◽  
Xu Han ◽  
Jian Li ◽  
Chunpu Li ◽  
Hong Liu
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Reaction Conditions

A mild and facile Cp*Rh(III)-catalyzed C–H activation and intramolecular cascade annulation protocol has been proposed for the furnishing of highly fused isochromeno-1,2-benzothiazines scaffolds using S-phenylsulfoximides and 4-diazoisochroman-3-imine as substrates under room temperature. This method features diverse substituents and functional groups tolerance and relatively mild reaction conditions with moderate to excellent yields. Additionally, retentive configuration of sulfoximides in the conversion has been verified.

scholarly journals Ring-Opening of Cyclodextrins: An Efficient Route to Pure Maltohexa-, Hepta-, and Octaoses

Organics ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 287-305
Author(s):  
Matthieu Pélingre ◽  
Dindet Steve-Evanes Koffi Teki ◽  
Jamal El-Abid ◽  
Vincent Chagnault ◽  
José Kovensky ◽  
...  
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Ring Opening ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Strong Potential ◽  
Efficient Route ◽  
Biotechnological Processes

Many preparations of maltooligosaccharides have been described in literature, essentially using enzymatic or biotechnological processes. These compounds, derived from starch, are well-known as prebiotic agents. The use of maltohexa-, hepta-, and octaoses as synthons in organic synthesis was also well documented in literature. They can indeed be obtained as single compounds by the cyclodextrins’ ring-opening. This reaction has been studied for many years, varying the protecting and functional groups and the reaction conditions, leading to functionalized oligomaltoses. These compounds are of wide interest in various fields. They have a strong potential as scaffolds for multivalence in chemobiology, as building blocks for the production of biomimetic pseudo-glycopeptides, as well as monomers for the preparation of materials. In view of the importance of these oligomaltoses, this review focuses on the different methodologies allowing access to them via chemical and enzymatic ring-opening of cyclodextrins.

scholarly journals Synthesis of α,β-unsaturated ketones through nickel-catalysed aldehyde-free hydroacylation of alkynes

2021 ◽  
Author(s):  
Joon Ho Rhlee ◽  
Saikat Maiti ◽  
Ho Seung Lee ◽  
Soochan Lee ◽  
Jaehyun Park ◽  
...  
Keyword(s):  
Transition Metal ◽  
Functional Groups ◽  
Room Temperature ◽  
Functional Materials ◽  
Ruthenium Catalysts ◽  
Terminal Alkynes ◽  
Acylating Agent ◽  
Reaction Conditions ◽  
Coupling Process ◽  
Unsaturated Ketones

Abstract α,β-Unsaturated ketones are common feedstocks in functional materials, pharmaceuticals and natural compounds. Transition metal-catalysed hydroacylation reactions of alkynes using aldehydes have been widely applied for the atom-economical synthesis of α,β-unsaturated ketones through chemoselective aldehydic C–H activation. However, previous hydroacylation reactions using rhodium, cobalt, or ruthenium catalysts require chelating moiety-bearing aldehydes to prevent undesired decarbonylative product via an unstable acyl-metal-H complex. Herein, we report a nickel-catalysed reductive and anti-Markovnikov selective coupling process to afford non-tethered E-enones from terminal alkynes through an acyl-nickel-thiopyridine complex in the presence of zinc metal as a reducing agent. Utilization of a thioester as an acylating agent and water as a hydrogen donor enables this mechanistically distinctive and aldehyde-free hydroacylation of terminal alkynes under mild reaction conditions at room temperature, with a broad substrate scope including versatile functional groups and even simple aryl and alkyl moieties.

scholarly journals Dioxasilepanyl Group as a Versatile Organometallic Unit: Studies in Stability, Reactivity, and Utility

2021 ◽  
Author(s):  
Hayate Saito ◽  
Jun Shimokawa ◽  
Hideki Yorimitsu
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Functional Group ◽  
Reaction Conditions ◽  
Multistep Synthesis

Organic synthesis is orchestrated based on precise choices of functional groups and reactions employed. In a multistep synthesis, an ideal functional group should be orthogonal to various reaction conditions and...

Recent Developments on Ultrasound-Assisted Synthesis of Bioactive N-Heterocycles at Ambient Temperature

2017 ◽  
Vol 70 (8) ◽  
pp. 872 ◽  
Author(s):  
Bubun Banerjee
Keyword(s):  
Ambient Temperature ◽  
Organic Synthesis ◽  
Ultrasonic Irradiation ◽  
Room Temperature ◽  
Biological Activities ◽  
Reaction Conditions ◽  
Biologically Relevant ◽  
Naturally Occurring ◽  
Recent Developments ◽  
Ultrasound Assisted

N-Heterocycles represent privileged structural subunits well distributed in naturally occurring compounds with immense biological activities. The last decade has seen a tremendous practice to carry out reactions at ambient temperature avoiding harsh reaction conditions. By applying ultrasonic radiation in organic synthesis we can make synthetic protocols more sustainable and can carry out reactions at room temperature avoiding the traditional thermal harsh reaction conditions. Therefore the synthesis of biologically relevant N-heterocycles at room temperature under the influence of ultrasonic irradiation is one of the advancing areas in the 21st century among organic chemists. The present review summarises the latest developments on ultrasound-assisted synthesis of biologically relevant N-heterocycles at ambient temperature.

scholarly journals Cu(OTf)2-Catalyzed Beckmann Rearrangement of Ketones Using Hydroxylamine-O-sulfonic Acid (HOSA)

Synthesis ◽  
2019 ◽  
Vol 51 (19) ◽  
pp. 3709-3714 ◽  
Author(s):  
Sailu Munnuri ◽  
Saumya Verma ◽  
Dinesh Chandra ◽  
Raghunath Reddy Anugu ◽  
John R. Falck ◽  
...  
Keyword(s):  
Functional Groups ◽  
Sulfonic Acid ◽  
Beckmann Rearrangement ◽  
Water Soluble ◽  
Reaction Conditions ◽  
Secondary Amides

The Beckmann rearrangement (BKR) of ketones to secondary amides often requires harsh reaction conditions that limit its practicality and scope. Herein, the Cu(OTf)2-catalyzed BKR of ketones under mild reaction conditions using hydroxylamine-O-sulfonic acid (HOSA), a commercial water soluble aminating agent, is described. This method is compatible with most functional groups and directly provides the desired amides in good to excellent yields.

Green Photoorganocatalytic Synthesis of Phenols from Arylboronic Acids

Synlett ◽  
2017 ◽  
Vol 29 (10) ◽  
pp. 1324-1328 ◽  
Author(s):  
Christoforos Kokotos ◽  
Ioanna Sideri ◽  
Errika Voutyritsa
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Boronic Acids ◽  
Light Irradiation ◽  
Reaction Conditions ◽  
Arylboronic Acids ◽  
Water As Solvent ◽  
High Yields

A green and cheap protocol for the photocatalytic hydroxylation of arylboronic acids is presented. 2,2-Dimethoxy-2-phenylacetophenone proved to be the best photoinitiator, among a range of organocatalysts in promoting this reaction. This photocatalytic protocol can be expanded into a wide substrate scope of aromatic boronic acids bearing various functional groups, leading to the corresponding phenols in good to high yields under mild reaction conditions, which include water as solvent, light irradiation provided from standard light-bulbs at room temperature.

scholarly journals Zinc (II)-Mediated Selective O-Benzylation of 2-Oxo-1,2-Dihydropyridines Systems

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1784 ◽  
Author(s):  
Qifan Zhou ◽  
Fangyu Du ◽  
Xinjie Liang ◽  
Wenqiang Liu ◽  
Ting Fang ◽  
...  
Keyword(s):  
Natural Products ◽  
Ternary System ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Critical Role ◽  
New Method ◽  
Reaction Conditions ◽  
Highly Effective ◽  
Benzyl Halides ◽  
Synthetic Intermediates

The selective O-benzylation of 2-oxo-1,2-dihydropyridines plays a critical role in organic synthesis of natural products and biological active molecules. Herein we report a novel ternary system of ZnO, ZnCl2 and N,N-diisopropylethylamine (DIEA), that is highly effective for selective O-benzylation of 2-oxo-1,2-dihydropyridines using abundant substituted benzyl halides and related substituted 2-oxo-1,2-dihydropyridines compounds. This process allows access to a variety of O-benzyl products under mild reaction conditions, which are important synthetic intermediates in the protection of functional groups, and represents a new method toward the development for the O-benzylation of 2-oxo-1,2-dihydropyridines.

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

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