Route to Air and Moisture Stable β-Difluoroboryl Acrylamides

Fritzemeier, Russell G.; Medici, Eric; Szwetkowski, Connor; Wonilowicz, Laura G.; Sibley, Christopher D.; Slebodnick, Carla; Santos, Webster L.

doi:10.1021/acs.orglett.9b03031

Cited by 5 publications

(4 citation statements)

References 48 publications

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“…For the fluorinated amide product E - 2n , suitable crystals for X-ray diffraction analysis could be obtained, showing a strong interaction between the amide carbonyl and the boron atom (O–B bond distance 1.735 Å) with virtually no conjugation between the Bpin moiety and the C–C double bond. These observations are in complete agreement with previous X-ray studies on β-borylacrylamides performed by the groups of Santos 18 and Gilmour. 19 Interestingly, mildly acidic N–H bonds of enantiopure α-amino esters derived from l -valine ( E - 2p ) and l -Bn-cysteine ( E- 2q ) were well tolerated, affording the corresponding products with no erosion of the enantiomeric purity.…”

Section: Resultssupporting

confidence: 92%

“… 17 The anti-hydroboration of NH propiolamides mediated by stoichiometric amounts of strong bases (typically BuLi) has also been reported. 18 An important drawback from these methods is the modest reactivity, limited scope, and incomplete anti-stereoselectivity with alkyl-substituted alkynes. The use of PMe 3 instead of PBu 3 goes some way to addressing this limitation, 17a but PMe 3 is an expensive reagent, pyrophoric, has an unpleasant odor, and is toxic.…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, metal-free protocols have been developed for anti-hydroboration of alkynoic acid derivatives with HBpin catalyzed by trialkylphosphines (typically PBu 3 ) . The anti-hydroboration of NH propiolamides mediated by stoichiometric amounts of strong bases (typically BuLi) has also been reported . An important drawback from these methods is the modest reactivity, limited scope, and incomplete anti-stereoselectivity with alkyl-substituted alkynes.…”

Section: Introductionmentioning

confidence: 99%

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One-Metal/Two-Ligand for Dual Activation Tandem Catalysis: Photoinduced Cu-Catalyzed Anti-hydroboration of Alkynes

et al. 2022

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A dual catalyst system based on ligand exchange of two diphosphine ligands possessing different properties in a copper complex has been devised to merge metal- and photocatalytic activation modes. This strategy has been applied to the formal anti-hydroboration of activated internal alkynes via a tandem sequence in which Cu/Xantphos catalyzes the B 2 pin 2 - syn -hydroboration of the alkyne whereas Cu/BINAP serves as a photocatalyst for visible light-mediated isomerization of the resulting alkenyl boronic ester. Photochemical studies by means of UV–vis absorption, steady-state and time-resolved fluorescence, and transient absorption spectroscopy have allowed characterizing the photoactive Cu/BINAP species in the isomerization reaction and its interaction with the intermediate syn -alkenyl boronic ester through energy transfer from the triplet excited state of the copper catalyst. In addition, mechanistic studies shed light into catalyst speciation and the interplay between the two catalytic cycles as critical success factors.

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Section: Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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One-Metal/Two-Ligand for Dual Activation Tandem Catalysis: Photoinduced Cu-Catalyzed Anti-hydroboration of Alkynes

et al. 2022

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“…4A ). For example, 3a readily underwent the Suzuki-Miyaura reaction under the palladium-catalyzed conditions, affording the arylation product 6a with an exclusive Z configuration ( 58 ). Besides the cross-coupling reaction, treatment of 3a with a strong oxidant such as NaBO 3 ⋅4H 2 O resulted in the formation of amide 6b .…”

Section: Resultsmentioning

confidence: 99%

Alkynone β-trifluoroborates: A new class of amine-specific biocompatible click reagents

Teng

Zhang

et al. 2023

Sci. Adv.

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Amine-targeting reactions that work under biocompatible conditions or in water are green processes that are extremely useful for the synthesis of functional materials and biotherapeutics. Unfortunately, despite the usefulness of this reaction, there are very few good amine-specific click methods reported thus far. Here, we report an amine-specific click reagent using alkynone β-trifluoroborates as the electrophiles. These boron-containing alkynyl reagents exhibit extremely high chemoselectivity toward amines even in the presence of thiols. The resulting oxaboracycle products are bench-stable, displaying the reactivities of both organoborates and enaminones. Intrinsic advantages of this methodology include benign reaction conditions, operational simplicity, remarkable product stability, and excellent chemoselectivity, which satisfy the criteria of click chemistry and demonstrate the high potential in bioconjugation. Hence, this water-based chemical approach is also applicable to the modification of native amino acids, peptides, and proteins. Ultimately, the essential role of water during the reaction was elucidated.

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Copper‐Catalyzed Synthesis of α‐Trifluoromethylacrylates from Trifluoroborylacrylates via Stereoretentive Radical Trifluoromethylation

Jos

Santos

2020

Adv Synth Catal

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We report the synthesis of α‐trifluoromethylacrylates from α‐trifluoroborylacrylates via a stereoretentive radical trifluoromethylation with inexpensive reagents NaSO2CF3 and TBHP at room temperature. Under these conditions, a wide substrate scope afforded the (E)‐diastereomer exclusively in moderate to good yield. The utility of the reaction products is demonstrated in the synthesis of phenyl‐4H‐pyran, a potent and selective class of IKCa channel blockers.

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Route to Air and Moisture Stable β-Difluoroboryl Acrylamides

Cited by 5 publications

References 48 publications

One-Metal/Two-Ligand for Dual Activation Tandem Catalysis: Photoinduced Cu-Catalyzed Anti-hydroboration of Alkynes

One-Metal/Two-Ligand for Dual Activation Tandem Catalysis: Photoinduced Cu-Catalyzed Anti-hydroboration of Alkynes

Alkynone β-trifluoroborates: A new class of amine-specific biocompatible click reagents

Copper‐Catalyzed Synthesis of α‐Trifluoromethylacrylates from Trifluoroborylacrylates via Stereoretentive Radical Trifluoromethylation

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