Asymmetric Synthesis of Chiral 1,2‐Bis(Boronic) Esters Featuring Acyclic, Non‐Adjacent 1,3‐Stereocenters

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(5)

Опубликована: Дек. 15, 2023

The construction of acyclic, non-adjacent 1,3-stereogenic centers, prevalent motifs in drugs and bioactive molecules, has been a long-standing synthetic challenge due to acyclic nucleophiles being distant from the chiral environment. In this study, we successfully synthesized highly valuable 1,2-bis(boronic) esters featuring nonadjacent 1,3-stereocenters. Notably, reaction selectively produces migratory coupling products rather than alternative deborylative allylation or direct byproducts. This approach introduces new activation mode for selective transformations gem-diborylmethane asymmetric catalysis. Additionally, found that other gem-diborylalkanes, previously challenging steric hindrance, also participated reaction. incorporation 1,2-bis(boryl)alkenes facilitated diversification alkenyl two boron moieties our target compounds, thereby enabling access broad array versatile molecules. DFT calculations were performed elucidate mechanism shed light on factors responsible observed excellent enantioselectivity diastereoselectivity. These determined arise ligand-substrate repulsions syn-addition transition state.

Язык: Английский

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Enantioselective Construction of Chiral Sulfides via Catalytic Electrophilic Azidothiolation and Oxythiolation of N-Allyl Sulfonamides

ACS Catalysis, Год журнала: 2019, Номер 9(8), С. 6896 - 6902

Опубликована: Июль 2, 2019

An efficient and convenient pathway was developed for enantioselective synthesis of chiral sulfides by bifunctional selenide-catalyzed electrophilic azidothiolation oxythiolation N-allyl sulfonamides. By this protocol, a variety vicinal azidosulfides oxysulfides were obtained in good yields with high enantioselectivities diastereoselectivities. In transformation, not only arylthiolating reagents but also wide range alkylthiolating worked very well. The practical application method elucidated further transformations the products into diversified compounds.

Язык: Английский

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Ring-Expansion Induced 1,2-Metalate Rearrangements: Highly Diastereoselective Synthesis of Cyclobutyl Boronic Esters

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(12), С. 5515 - 5520

Опубликована: Март 7, 2020

The broad synthetic utility of organoboron compounds stems from their ready ability to undergo 1,2-migrations. Normally, such shifts are induced by α-leaving groups or reactions alkenyl boronates with electrophiles. Herein, we present a new strategy induce 1,2-metalate rearrangements, via ring expansion vinylcyclopropyl boronate complexes activated This leads cyclopropane-stabilized carbocation, which triggers and concomitant rearrangement. novel process delivers medicinally relevant 1,2-substituted cyclobutyl boronic esters high levels diastereoselectivity. A wide range organolithiums Grignard reagents, electrophiles, can be used. methodology was applied short, stereoselective synthesis (±)-grandisol. Computational studies indicate that the reaction proceeds nonclassical carbocation followed anti-1,2-migration.

Язык: Английский

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Enantio‐ and Diastereoselective, Lewis Base Catalyzed, Cascade Sulfenoacetalization of Alkenyl Aldehydes

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(36), С. 12486 - 12490

Опубликована: Июль 11, 2019

Abstract A catalytic, enantio‐, and diastereoselective formation of sulfenyl acetals bearing multiple stereogenic centers is reported. Alkenyl aldehydes undergo a chiral thiiranium ion initiated cascade starting with intramolecular capture by formyl group termination HFIP solvent. This method provides one‐pot synthesis dihydropyran 1,3‐disubstituted isochroman in good to excellent yield high levels diastereo‐ (up >99:1 dr) enantiocontrol 99:1 er).

Язык: Английский

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Nickel‐Catalyzed Regioselective Hydroalkylation and Hydroarylation of Alkenyl Boronic Esters

Angewandte Chemie, Год журнала: 2019, Номер 131(39), С. 13992 - 13997

Опубликована: Июль 8, 2019

Abstract Metal hydride catalyzed hydrocarbonation reactions of alkenes are an efficient approach to construct new carbon–carbon bonds from readily available alkenes. However, the regioselectivity remains challenging be controlled. In nickel (NiH) hydrocarbonation, linear selectivity is most often obtained because relative stability Ni–alkyl intermediate over its branched counterpart. Herein, we show that boronic pinacol ester (Bpin) group directs a Ni‐catalyzed occur at adjacent carbon center, resulting in formal branch selectivity. Both alkyl and aryl halides can used as electrophiles this providing access wide range secondary Bpin derivatives, which valuable building blocks synthetic chemistry. The utility method demonstrated by late‐stage functionalization natural products drug molecules, synthesis anticancer agent, iterative syntheses.

Язык: Английский

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