Direct Formic Acid Mediated<i>Z</i>‐Selective Reductive Coupling of Dienes and Aldehydes

Cooze, Christopher; Dada, Raphael; Lundgren, Rylan J.

doi:10.1002/anie.201905540

Cited by 26 publications

(19 citation statements)

References 72 publications

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“…While no diastereoselectivity was observed by using linalool derivatives, acyclic olefins bearing allylic stereocenters were investigated in our N atom transfer reaction to determine if allylic strain could influence the reaction outcome. In contrast to epoxidation, whose stereochemical control models appear in textbooks and has been applied in natural product total synthesis, , reports of α-substituted acyclic olefins in metal-catalyzed aziridination reactions are surprisingly rare . To address this gap, we investigated two olefins to determine if allylic strain could be used to control the diastereoselectivity of N -aryl aziridination.…”

Section: Results and Discussionmentioning

confidence: 99%

Rh₂(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

et al. 2021

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The development of the first intermolecular Rh2(II)-catalyzed aziridination of olefins using anilines as nonactivated N atom precursors and an iodine(III) reagent as the stoichiometric oxidant is reported. This reaction requires the transfer of an N-aryl nitrene fragment from the iminoiodinane intermediate to a Rh2(II) carboxylate catalyst; in the absence of a catalyst only diaryldiazene formation was observed. This N-aryl aziridination is general and can be successfully realized by using as little as 1 equiv of the olefin. Di-, tri-, and tetrasubstituted cyclic or acylic olefins can be employed as substrates, and a range of aniline and heteroarylamine N atom precursors are tolerated. The Rh2(II)-catalyzed N atom transfer to the olefin is stereospecific as well as chemo- and diastereoselective to produce the N-aryl aziridine as the only amination product. Because the chemistry of nonactivated N-aryl aziridines is underexplored, the reactivity of N-aryl aziridines was explored toward a range of nucleophiles to stereoselectively access privileged 1,2-stereodiads unavailable from epoxides, and removal of the N-2,4-dinitrophenyl group was demonstrated to show that functionalized primary amines can be constructed.

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Section: Results and Discussionmentioning

confidence: 99%

Rh₂(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

et al. 2021

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“…Potentially reactive units like aryl halides (2,8,11), NH-groups (4, 5), nitrile (7), aryl silane (11), and aryl acrylate (12) are tolerated on the aryl boron group. The aryl aldehyde partner can feature electron-donating group (15) or electron-withdrawing groups (16,17) as well as phenol (18) or ortho-Br substitution (19). The dienoate partner can feature either alkyl or aryl groups at the δ-position (2, 20−23).…”

Section: ■ Introductionmentioning

confidence: 99%

“…Dienamides, including those featuring the Weinreb amide, engaged in the reaction to give products as nearly single diastereomers and in ≥95% ee (25, 26). In certain cases (9,10,15,22), diastereoselectivities were reduced to ∼90:10 (see below for a discussion).…”

Section: ■ Introductionmentioning

confidence: 99%

Diastereo-, Enantio-, and Z-Selective α,δ-Difunctionalization of Electron-Deficient Dienes Initiated by Rh-Catalyzed Conjugate Addition

et al. 2021

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Metal-catalyzed enantioselective conjugate additions are highly reliable methods for stereoselective synthesis; however, multicomponent reactions that are initiated by conjugate arylation of acyclic π-systems are rare. These reactions generally proceed with poor diastereoselectivity while requiring basic, moisture sensitive organometallic nucleophiles. Here, we show that Rh-catalysts supported by a tetrafluorobenzobarrelene ligand (Ph-tfb) enable the enantio-, diastereo-, and Z-selective α,δ-difunctionalization of electron-deficient 1,3-dienes with organoboronic acid nucleophiles and aldehyde electrophiles to generate Z-homoallylic alcohols with three stereocenters. The reaction accommodates diene substrates activated by ester, amide, ketone, or aromatic groups and can be used to couple aryl, alkenyl, or alkyl aldehydes. Diastereoselective functionalization of the Z-olefin unit in the addition products allows for the generation of compounds with five stereocenters in high dr and ee. Mechanistic studies suggest aldehyde allylrhodation is the rate-determining step, and unlike reactions of analogous Rh-enolates, the Rh-allyl species generated by δ-arylation undergoes aldehyde trapping rather than protonolysis, even when water is present as a cosolvent. These findings should have broader implications in the use of privileged metal-catalyzed conjugate addition reactions as entry points toward the preparation of acyclic molecules containing nonadjacent stereocenters.

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“…Moreover, 1,3-dienes are a class of synthetically versatile compounds in organic chemistry, which are easily converted into highly functionalized molecules via diversified strategies based on transition metal catalysis or photoredox catalysis. − The reductive coupling between 1,3-dienes and carbonyl compounds or imines is particularly appealing, which affords synthetically useful homoallylic alcohols or amines . Various catalytic systems based on different transition metal catalysts, including Ni, − Ru, − Rh, − Ir, − and Cu, − were disclosed. One of the notable reactions was the copper(I)-catalyzed asymmetric reductive allylation of ketones with 1,3-dienes. , Strikingly, the coupling partner was expanded to CO 2 under copper(I) catalysis, which also produced chiral homoallyl alcohols after extensive reduction. , …”

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confidence: 99%

Copper(I)-Catalyzed Regioselective Asymmetric Addition of 1,4-Pentadiene to Ketones

et al. 2021

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By using commercially available 1,4-pentadiene as a pronucleophile, a copper(I)-catalyzed regioselective asymmetric allylation of ketones is achieved. A variety of chiral tertiary alcohols bearing a terminal (Z)-1,3-diene unit are generated in high (Z)/(E) ratio and high enantioselectivity. Both aromatic ketones and aliphatic ketones serve as suitable substrates. Furthermore, the reactions with (E)-C1(alkyl)-1,4-dienes proceed in moderate yields with acceptable enantioselectivity but with low (Z,E)/others ratio, which demonstrates the partial isomerization of (E)-allylcopper(I) species to (Z)-allylcopper(I) species through 1,3-migration. Subsequent Heck reaction and olefin metathesis compensate for the low efficiency with C1-1,4-dienes. The synthetic utility of the product is further demonstrated by a copper(I)-catalyzed regioselective borylation of the 1,3-diene group.

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Direct Formic Acid MediatedZ‐Selective Reductive Coupling of Dienes and Aldehydes

Cited by 26 publications

References 72 publications

Rh₂(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

Rh₂(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

Diastereo-, Enantio-, and Z-Selective α,δ-Difunctionalization of Electron-Deficient Dienes Initiated by Rh-Catalyzed Conjugate Addition

Copper(I)-Catalyzed Regioselective Asymmetric Addition of 1,4-Pentadiene to Ketones

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Direct Formic Acid MediatedZ‐Selective Reductive Coupling of Dienes and Aldehydes

Cited by 26 publications

References 72 publications

Rh2(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

Rh2(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

Diastereo-, Enantio-, and Z-Selective α,δ-Difunctionalization of Electron-Deficient Dienes Initiated by Rh-Catalyzed Conjugate Addition

Copper(I)-Catalyzed Regioselective Asymmetric Addition of 1,4-Pentadiene to Ketones

Contact Info

Product

Resources

About

Rh₂(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors

Rh₂(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors