A Transient Directing Group Strategy Enables Enantioselective Reductive Heck Hydroarylation of Alkenes

<p>Metal-coordinating directing groups have seen extensive use in the field of transition-metal-mediated functionalization of alkenes; however, their waste-generating installation and removal steps limit the efficiency and practicality of reactions that rely on their use. Inspired by developments in the field of C–H activation, herein we report a transient directing group approach to reductive Heck hydroarylation of alkenyl benzaldehyde substrates that proceeds under mild conditions. Highly stereoselective migratory insertion is facilitated by in situ formation of an imine from catalytic amounts of commercially available amino acid additive. Computational studies reveal an unusual mode of enantioinduction by the remote chiral center in the transient directing group.</p>

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Ultra-Small Pd(0) Nanoparticles into a Designed Semisynthetic Lipase: An Efficient and Recyclable Heterogeneous Biohybrid Catalyst for the Heck Reaction under Mild Conditions

Molecules ◽

10.3390/molecules23092358 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2358 ◽

Cited By ~ 7

Author(s):

David Lopez-Tejedor ◽

Blanca de las Rivas ◽

Jose M. Palomo

Keyword(s):

Catalytic Activity ◽

Protein Structure ◽

Heck Reaction ◽

Catalytic Performance ◽

Reducing Agent ◽

Chemically Modified ◽

Mild Conditions ◽

In Situ Formation ◽

Geobacillus Thermocatenulatus

A novel heterogeneous enzyme-palladium (Pd) (0) nanoparticles (PdNPs) bionanohybrid has been synthesized by an efficient, green, and straightforward methodology. A designed Geobacillus thermocatenulatus lipase (GTL) variant genetically and then chemically modified by the introduction of a tailor-made cysteine-containing complementary peptide- was used as the stabilizing and reducing agent for the in situ formation of ultra-small PdNPs nanoparticles embedded on the protein structure. This bionanohybrid was an excellent catalyst in the synthesis of trans-ethyl cinnamate by Heck reaction at 65 °C. It showed the best catalytic performance in dimethylformamide (DMF) containing 10–25% of water as a solvent but was also able to catalyze the reaction in pure DMF or with a higher amount of water as co-solvent. The recyclability and stability were excellent, maintaining more than 90% of catalytic activity after five cycles of use.

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Mechanistic Studies on Nitrosation–Deaminocyclization of Mono-Carbamoylated Vicinal Amino Alcohols and Diols: A New Preparative In Situ Formation of Ethanediazo Hydroxide for the Ethylation of Carboxylates under Mild Conditions

Bulletin of the Chemical Society of Japan ◽

10.1246/bcsj.77.1217 ◽

2004 ◽

Vol 77 (6) ◽

pp. 1217-1227 ◽

Cited By ~ 7

Author(s):

Masumi Suzuki ◽

Takeshi Sugai

Keyword(s):

Amino Alcohols ◽

Mechanistic Studies ◽

Mild Conditions ◽

In Situ Formation

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CO2as a hydrogen vector – transition metal diamine catalysts for selective HCOOH dehydrogenation

Dalton Transactions ◽

10.1039/c6dt04638j ◽

2017 ◽

Vol 46 (5) ◽

pp. 1670-1676 ◽

Cited By ~ 19

Author(s):

Cornel Fink ◽

Gábor Laurenczy

Keyword(s):

Aqueous Solution ◽

Hydrogen Production ◽

Transition Metal ◽

Formic Acid ◽

Catalytic Dehydrogenation ◽

Mild Conditions ◽

Adjustable Rate

The homogeneous catalytic dehydrogenation of formic acid in aqueous solution provides an efficientin situmethod for hydrogen production, under mild conditions, and at an adjustable rate.

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In-situ formation, thermal decomposition, and adsorption studies of transition metal carbonyl complexes with short-lived radioisotopes

Radiochimica Acta ◽

10.1515/ract-2013-2198 ◽

2014 ◽

Vol 102 (12) ◽

Cited By ~ 9

Author(s):

Julia Even ◽

Alexander Yakushev ◽

Christoph Emanuel Düllmann ◽

Jan Dvorak ◽

Robert Eichler ◽

...

Keyword(s):

Thermal Decomposition ◽

Transition Metal ◽

Metal Carbonyl ◽

Carbonyl Complexes ◽

Adsorption Studies ◽

Metal Carbonyl Complexes ◽

In Situ Formation

AbstractWe report on the

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ChemInform Abstract: In situ Formation of NOx and Br Anion for Aerobic Oxidation of Benzylic Alcohols Without Transition Metal.

ChemInform ◽

10.1002/chin.201024043 ◽

2010 ◽

Vol 41 (24) ◽

pp. no-no

Author(s):

Guanyu Yang ◽

Wei Wang ◽

Weimin Zhu ◽

Cunbin An ◽

Xinqin Gao ◽

...

Keyword(s):

Transition Metal ◽

Aerobic Oxidation ◽

Benzylic Alcohols ◽

In Situ Formation

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In situ activation of benzyl alcohols with XtalFluor-E: formation of 1,1-diarylmethanes and 1,1,1-triarylmethanes through Friedel–Crafts benzylation

Organic & Biomolecular Chemistry ◽

10.1039/c4ob02655a ◽

2015 ◽

Vol 13 (8) ◽

pp. 2243-2246 ◽

Cited By ~ 21

Author(s):

Justine Desroches ◽

Pier Alexandre Champagne ◽

Yasmine Benhassine ◽

Jean-François Paquin

Keyword(s):

Transition Metal ◽

Lewis Acid ◽

Benzyl Alcohols ◽

Mild Conditions ◽

In Situ Activation ◽

Wide Range ◽

Strong Lewis Acid

The Friedel–Crafts benzylation of arenes using benzyl alcohols activated in situ with XtalFluor-E is described. A wide range of 1,1-diarylmethanes and 1,1,1-triarylmethanes were prepared under simple and mild conditions, without the need for a transition metal or a strong Lewis acid.

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In situ Formation of NOx and Br Anion for Aerobic Oxidation of Benzylic Alcohols without Transition Metal

Synlett ◽

10.1055/s-0029-1219202 ◽

2010 ◽

Vol 2010 (03) ◽

pp. 437-440 ◽

Cited By ~ 22

Author(s):

Guanyu Yang ◽

Maoping Song ◽

Wei Wang ◽

Weimin Zhu ◽

Cunbin An ◽

...

Keyword(s):

Transition Metal ◽

Aerobic Oxidation ◽

Benzylic Alcohols ◽

In Situ Formation

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Step-Economical C–H Activation Reactions Directed by In Situ Amidation

Synthesis ◽

10.1055/s-0040-1707124 ◽

2020 ◽

Vol 52 (21) ◽

pp. 3211-3218

Author(s):

Yunyun Liu ◽

Baoli Zhao

Keyword(s):

Transition Metal ◽

Bond Activation ◽

Short Review ◽

Metal Catalysts ◽

Transition Metal Catalysts ◽

Directing Group ◽

Crude Material

Owing to the inherent ability of amides to chelate transition-metal catalysts, amide-directed C–H activation reactions constitute a major tactic in directed C–H activation reactions. While the conventional procedures for these reactions usually involve prior preparation and purification of amide substrates before the C–H activation, the step economy is actually undermined by the operation of installing the directing group (DG) and related substrate purification. In this context, directed C–H activation via in situ amidation of the crude material provides a new protocol that can significantly enhance the step economy of amide-directed C–H activation. In this short review, the advances in C–H bond activation reactions mediated or initiated by in situ amidation are summarized and analyzed.1 Introduction2 In Situ Amidation in Aryl C–H Bond Activation3 In Situ Amidation in Alkyl C–H Bond Activation4 Annulation Reactions via Amidation-Mediated C–H Activation5 Remote C–H Activation Mediated by Amidation6 Conclusion

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[bmim]PF6/KOH: A Recyclable Catalytic System for an Azide–Arylacetaldehyde [3 + 2] Cycloaddition

Journal of Chemical Research ◽

10.3184/174751917x15094552081152 ◽

2017 ◽

Vol 41 (11) ◽

pp. 631-635

Author(s):

Yuqin Jiang ◽

Kai Wu ◽

Xuxia Tan ◽

Dandan Zhang ◽

Wenpei Dong ◽

...

Keyword(s):

Transition Metal ◽

Organic Solvent ◽

Catalytic System ◽

Room Temperature ◽

Reaction Medium ◽

Metal Catalyst ◽

Transition Metal Catalyst ◽

Green Protocol ◽

Mild Conditions

A fast and green protocol for the synthesis of 1,4-disubstituted 1,2,3-triazoles from azides and arylacetaldehydes at room temperature was developed using [bmim]PF6/KOH as the reaction medium. It was found that the in situ-generated carbene from [bmim]PF6/KOH acted as the catalyst. In the absence of a transition-metal catalyst and organic solvent, this azide–arylacetaldehyde [3 + 2] cycloaddition proceeds efficiently, with high levels of regioselectivity, broad range of substrates, excellent yields and simple operation under mild conditions.

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