Photocatalytic three-component asymmetric sulfonylation via direct C(sp3)-H functionalization

Abstract The direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (> 50 examples, up to > 50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides new access to enantioenriched compounds starting from the abundant hydrocarbon compounds.

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LED Light Sources in Organic Synthesis: An Entry to A Novel Approach

Letters in Organic Chemistry ◽

10.2174/1570178618666210916164132 ◽

2021 ◽

Vol 18 ◽

Author(s):

Aparna Das

Keyword(s):

Organic Compounds ◽

Organic Synthesis ◽

Photochemical Reaction ◽

Low Cost ◽

Environmentally Friendly ◽

Photochemical Reactions ◽

Light Sources ◽

Blue Led ◽

Oxidation Reduction ◽

Novel Approach

: In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally friendly, and sustainable technology. Compared to other light sources in photochemical reaction, LEDs have advantages in terms of efficiency, power, compatibility, and environmentally-friendly nature. This review highlights the most recent advances in LED-induced photochemical reactions. The effect of white and blue LEDs in reactions such as oxidation, reduction, cycloaddition, isomerization, and sensitization is discussed in detail. No other reviews have been published on the importance of white and blue LED sources in the photocatalysis of organic compounds. Considering all the facts, this review is highly significant and timely.

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Biotechnology of Rhodococcus for the production of valuable compounds

Applied Microbiology and Biotechnology ◽

10.1007/s00253-020-10861-z ◽

2020 ◽

Vol 104 (20) ◽

pp. 8567-8594 ◽

Cited By ~ 1

Author(s):

Martina Cappelletti ◽

Alessandro Presentato ◽

Elena Piacenza ◽

Andrea Firrincieli ◽

Raymond J. Turner ◽

...

Keyword(s):

Waste Disposal ◽

Low Cost ◽

Value Added ◽

Industrial Wastes ◽

Bioactive Molecules ◽

High Concentration ◽

Metabolic Versatility ◽

Wide Range ◽

Valuable Compounds ◽

Medical Relevance

Abstract Bacteria belonging to Rhodococcus genus represent ideal candidates for microbial biotechnology applications because of their metabolic versatility, ability to degrade a wide range of organic compounds, and resistance to various stress conditions, such as metal toxicity, desiccation, and high concentration of organic solvents. Rhodococcus spp. strains have also peculiar biosynthetic activities that contribute to their strong persistence in harsh and contaminated environments and provide them a competitive advantage over other microorganisms. This review is focused on the metabolic features of Rhodococcus genus and their potential use in biotechnology strategies for the production of compounds with environmental, industrial, and medical relevance such as biosurfactants, bioflocculants, carotenoids, triacylglycerols, polyhydroxyalkanoate, siderophores, antimicrobials, and metal-based nanostructures. These biosynthetic capacities can also be exploited to obtain high value-added products from low-cost substrates (industrial wastes and contaminants), offering the possibility to efficiently recover valuable resources and providing possible waste disposal solutions. Rhodococcus spp. strains have also recently been pointed out as a source of novel bioactive molecules highlighting the need to extend the knowledge on biosynthetic capacities of members of this genus and their potential utilization in the framework of bioeconomy. Key points • Rhodococcus possesses promising biosynthetic and bioconversion capacities. • Rhodococcus bioconversion capacities can provide waste disposal solutions. • Rhodococcus bioproducts have environmental, industrial, and medical relevance.

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‘On-water’ organic synthesis: a green, highly efficient, low cost and reusable catalyst system for biaryl synthesis under aerobic conditions at room temperature

RSC Advances ◽

10.1039/c5ra09102k ◽

2015 ◽

Vol 5 (63) ◽

pp. 50655-50659 ◽

Cited By ~ 11

Author(s):

Bishwajit Saikia ◽

Preeti Rekha Boruah ◽

Abdul Aziz Ali ◽

Diganta Sarma

Keyword(s):

Organic Synthesis ◽

Room Temperature ◽

Low Cost ◽

Suzuki Reaction ◽

Catalyst System ◽

Reusable Catalyst ◽

Wide Range ◽

Biaryl Synthesis ◽

Phenylboronic Acids ◽

Operational Simplicity

The PdCl2/sucrose/K2CO3/H2O system showed the superb catalytic activity towards the Suzuki reaction of a wide range of aryl/heteroaryl halides with diverse phenylboronic acids at room temperature with operational simplicity and shorter reaction time.

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CuI-Catalyzed [3+2] Cycloaddition of Hindered Vinylidenebisphosphonates (VBP) with Azomethine Imines for Highly Regioselective Access to Dinitrogen-Heterobicycle-Containing Bisphosphonates

Synthesis ◽

10.1055/s-0036-1591555 ◽

2018 ◽

Vol 50 (13) ◽

pp. 2601-2607

Author(s):

Zhongxiang Zhu ◽

Qinghe Wang ◽

Dulin Kong ◽

Tiao Huang ◽

Mingshu Wu

Keyword(s):

Biological Activity ◽

Low Cost ◽

Cycloaddition Reaction ◽

Dipolar Cycloaddition ◽

Atom Economy ◽

Mild Conditions ◽

Synthetic Strategy ◽

Fused Heterocycles ◽

Azomethine Imines ◽

High Stereoselectivity

A concise, atom-economic, and highly regioselective synthetic strategy for the construction of several dinitrogen-fused heterocycles bearing bisphosphonates by 1,3-dipolar cycloaddition reaction of azomethine imines with tetraethyl vinylidene-1,1-bisphosphonate in the presence of CuI in toluene media has been developed. The targeted compounds were obtained in good yields and with excellent regioselectivity. This method for the synthesis of gem-bisphosphonates (BPs) is particularly attractive due to features such as low cost, mild conditions, atom economy, high stereoselectivity, and potential biological activity of the product.

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Palladium-Catalyzed Cross-Coupling of Gem-Bromofluoroalkenes with Alkylboronic Acids for the Synthesis of Alkylated Monofluoroalkenes

Molecules ◽

10.3390/molecules25235532 ◽

2020 ◽

Vol 25 (23) ◽

pp. 5532

Author(s):

Laëtitia Chausset-Boissarie ◽

Nicolas Cheval ◽

Christian Rolando

Keyword(s):

Organic Synthesis ◽

Functional Group ◽

Materials Science ◽

Cross Coupling ◽

High Yield ◽

Efficient Synthesis ◽

Mild Conditions ◽

Wide Range ◽

Palladium Catalyzed ◽

Novel Strategy

Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of gem-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the gem-bromofluoroalkenes geometry.

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Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

10.26434/chemrxiv.9722348 ◽

2019 ◽

Author(s):

Van Tran ◽

Zi-Qi Li ◽

Timothy Gallagher ◽

Joseph Derosa ◽

Peng Liu ◽

...

Keyword(s):

Organic Synthesis ◽

Cross Coupling ◽

Building Blocks ◽

Reductive Elimination ◽

Mechanistic Studies ◽

Mild Conditions ◽

Wide Range ◽

Directing Group ◽

Weakly Coordinating ◽

Analogous Method

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate azaheterocycle directing groups, that useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated in the facile reactivity of the β-γ alkene of the starting material, while the ε-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of analogous method with alkyne substrates. Mechanistic studies reveal the importance of the weakly coordinating directing group in dissociating to allow binding of the allyl moiety to facilitate C(sp3)–C(sp3) reductive elimination.

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Biocatalytic routes toward pharmaceutically important precursors and novel polymeric systems

Pure and Applied Chemistry ◽

10.1351/pac200577010209 ◽

2005 ◽

Vol 77 (1) ◽

pp. 209-226 ◽

Cited By ~ 17

Author(s):

Sunil K. Sharma ◽

Mofazzal Husain ◽

Rajesh Kumar ◽

Lynne A. Samuelson ◽

Jayant Kumar ◽

...

Keyword(s):

Organic Compounds ◽

Organic Synthesis ◽

Organic Solvents ◽

Low Cost ◽

Polymeric Materials ◽

Environmental Friendliness ◽

Polymeric Systems ◽

Wide Range ◽

Synthetic Sequence

The synthetic potential of enzymes related to organic synthesis has been applied profusely, especially since the introduction of their use in organic solvents. Enzymes offer the opportunity to carry out highly chemo-, regio-, and enantioselective transformations. The use of enzymes in the synthetic sequence provides unique advantages of efficiency and environmental friendliness. Owing to their low cost and applicability to a broad range of substrates, lipases have become the most versatile class of biocatalysts in organic synthesis. We have screened a battery of lipases to carry out highly selective reactions for the synthesis of a wide range of organic compounds and polymeric materials.

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Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

10.26434/chemrxiv.9722348.v1 ◽

2019 ◽

Author(s):

Van Tran ◽

Zi-Qi Li ◽

Timothy Gallagher ◽

Joseph Derosa ◽

Peng Liu ◽

...

Keyword(s):

Organic Synthesis ◽

Cross Coupling ◽

Building Blocks ◽

Reductive Elimination ◽

Mechanistic Studies ◽

Mild Conditions ◽

Wide Range ◽

Directing Group ◽

Weakly Coordinating ◽

Analogous Method

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate azaheterocycle directing groups, that useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated in the facile reactivity of the β-γ alkene of the starting material, while the ε-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of analogous method with alkyne substrates. Mechanistic studies reveal the importance of the weakly coordinating directing group in dissociating to allow binding of the allyl moiety to facilitate C(sp3)–C(sp3) reductive elimination.

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Base-Mediated 1,6-Aza-Michael Addition of Heterocyclic Amines and Amides to para-Quinone Methides Leading to Meclizine-, Hydroxyzine- and Cetirizine-like Architectures

Synthesis ◽

10.1055/s-0039-1690677 ◽

2019 ◽

Vol 51 (23) ◽

pp. 4434-4442 ◽

Cited By ~ 6

Author(s):

Deblina Roy ◽

Gautam Panda

Keyword(s):

Low Cost ◽

Scale Up ◽

Cost Effective ◽

Heterocyclic Amines ◽

Atom Economy ◽

Quinone Methides ◽

One Pot ◽

X Ray ◽

Wide Range ◽

Mild Temperature

An expeditious, cost-effective synthetic methodology for a wide range of nitrogen-containing unsymmetrical trisubstituted methanes (TRSMs) is reported. The synthesis involves base-mediated 1,6-conjugate addition of heterocyclic amines and amides to substituted para-quinone methides, giving the unsymmetrical TRSMs in moderate to very good yields (up to 83%) in one pot. The low cost, mild temperature, high atom economy and yields, easy scale-up and broad substrate scope are some of the salient features of this protocol. Further, the methodology could be extended for the synthesis of meclizine-, hydroxyzine- and cetirizine-like molecules. The structure of one such compound, 2,6-di-tert-butyl-4-((4-chlorophenyl)(4-methylpiperazin-1-yl)methyl)phenol, was determined by single crystal X-ray analysis.

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