Difunctionalization of C–C σ-Bonds Enabled by the Reaction of Bicyclo[1.1.0]butyl Boronate Complexes with Electrophiles: Reaction Development, Scope, and Stereochemical Origins

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(39), С. 16766 - 16775

Опубликована: Сен. 4, 2020

Difunctionalization reactions of C–C σ-bonds have the potential to streamline access molecules that would otherwise be difficult prepare. However, development such is challenging because are typically unreactive. Exploiting high ring-strain energy polycyclic carbocycles a common strategy weaken and facilitate reaction σ-bonds, but there limited examples highly strained being used in difunctionalization reactions. We demonstrate bicyclo[1.1.0]butyl boronate complexes (strain ca. 65 kcal/mol), which were prepared by reacting boronic esters with lithium, react electrophiles achieve diastereoselective central σ-bond unit. The shows broad substrate scope, range different successfully employed form diverse set 1,1,3-trisubstituted cyclobutanes (>50 examples) diastereoselectivity. diastereoselectivity observed has been rationalized based on combination experimental data DFT calculations, suggests separate concerted stepwise mechanisms operating, depending upon migrating substituent electrophile used.

Язык: Английский

---

Enantioselective, Lewis Base-Catalyzed Carbosulfenylation of Alkenylboronates by 1,2-Boronate Migration

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(46), С. 15621 - 15625

Опубликована: Ноя. 9, 2018

A catalytic, enantioselective method for the preparation of chiral, non-racemic, alkylboronic esters bearing two vicinal stereogenic centers is described. The reaction proceeds via a 1,2-migration zwitterionic thiiranium–boronate complex to give exclusively anti carbosulfenylation products. broad scope aryl groups migrate with good yield and excellent enantioselectivity (up 99:1 e.r.). Similarly, range di- trisubstituted alkenylboronic are competent partners. This provides access both secondary tertiary chiral esters.

Язык: Английский

---

Radical‐Induced 1,2‐Migrations of Boron Ate Complexes

Advanced Synthesis & Catalysis, Год журнала: 2019, Номер 362(11), С. 2077 - 2087

Опубликована: Дек. 24, 2019

Abstract 1,2‐Boron ate rearrangements represent a fundamental class of transformations to establish new C−C bonds while retaining the valuable boron moiety in product. In established ionic processes, complex is activated by an external electrophile induce 1,2‐migration from adjacent sp 3 or 2 carbon atom. Recently, two complementary radical polar crossover approaches have been explored for both classes, 1,2‐migrations and centers. This review describes general concepts this emerging research field summarizes recent developments radical‐induced carbon. magnified image

Язык: Английский

---

Practical and Modular Construction of C(sp³)-Rich Alkyl Boron Compounds

Journal of the American Chemical Society, Год журнала: 2020, Номер 143(1), С. 471 - 480

Опубликована: Дек. 21, 2020

Alkyl boronic acids and esters play an important role in the synthesis of C(sp3)-rich medicines, agrochemicals, material chemistry. This work describes a new type transition-metal-free mediated transformation to enable construction sterically hindered alkyl boron reagents practical modular manner. The broad generality functional group tolerance this method is extensively examined through variety substrates, including late-stage functionalization scaffolds relevant medicinal strategic significance approach, with as linchpins, demonstrated various downstream functionalizations compounds. two-step concurrent cross-coupling resembling formal flexible alkyl-alkyl couplings, provides general entry synthetically challenging high Fsp3-containing drug-like scaffolds.

Язык: Английский

---

Enantioselective Allylation of Alkenyl Boronates Promotes a 1,2-Metalate Rearrangement with 1,3-Diastereocontrol

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(13), С. 4921 - 4927

Опубликована: Март 23, 2021

Alkenyl boronates add to Ir(π-allyl) intermediates with high enantioselectivity. A 1,2-metalate shift forms a second C–C bond and sets 1,3-stereochemical relationship. The three-component coupling provides tertiary boronic esters that can undergo multiple additional functionalizations. An extension trisubstituted olefins three contiguous stereocenters.

Язык: Английский

---

Catalytic Asymmetric Diarylation of Internal Acyclic Styrenes and Enamides

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(18), С. 8389 - 8398

Опубликована: Апрель 28, 2022

Enantioselective transformations of olefins are among the most important strategies for asymmetric synthesis organic compounds. Chemo-, diastereo-, and stereoselective control reactions with internal acyclic alkenes construction functionalized alkanes still remain a persistent challenge. Here, we report palladium-catalyzed regiodivergent Heck-type diarylation alkenes. The 1,2-diarylation two accessible alkenes, cinnamyl carbamates enamides diazonium salts aromatic boronic acids, furnishes products containing vicinal stereogenic centers via stereospecific formation carbonyl coordination-assisted transient palladacycles. Moreover, migratory enables incontiguous stereocenters by an interrupted diastereoselective 1,3-chain-walking process. This protocol streamlines access to highly multisubstituted enantioenriched amine derivatives which embedded in key biologically active motifs.

Язык: Английский

---

Nickel-Catalyzed Regio- and Enantioselective Borylative Coupling of Terminal Alkenes with Alkyl Halides Enabled by an Anionic Bisoxazoline Ligand

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(25), С. 13603 - 13614

Опубликована: Июнь 6, 2023

Chiral boronic esters are a class of versatile building blocks. We describe herein an asymmetric nickel-catalyzed borylative coupling terminal alkenes with nonactivated alkyl halides. The success this reaction is ascribed to the application chiral anionic bisoxazoline ligand. This study provides three-component strategy access α- and β-stereogenic from easily accessible starting materials. protocol characterized by mild conditions, wide substrate scope high regio- enantioselectivity. also showcase value method in simplifying synthesis several drug molecules. Mechanistic studies suggest that generation enantioenriched bearing α-stereogenic center results stereoconvergent process, while enantioselectivity-controlling step β-stereocenter switched olefin migratory insertion due coordination ester group.

Язык: Английский

---

Ir‐Catalyzed Enantioselective Synthesis of gem‐Diborylalkenes Enabled by 1,2‐Boron Shift

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(32)

Опубликована: Июнь 15, 2023

Abstract Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2‐boron shift remained be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of carbonates at the elevated temperature. Notably, highly (bis‐boryl)alkenes array diversifications versatile molecules. Extensive experimental and computational studies conducted elucidate reaction mechanism DKR clarify origin enantioselectivities.

Язык: Английский

---

Ni-Catalyzed Regioselective Alkylarylation of Unactivated Alkenes in Amines Enabled by Cooperative Ligand Effects of Nitriles and Electron-Deficient Alkenes

Journal of the American Chemical Society, Год журнала: 2025, Номер 147(2), С. 1667 - 1676

Опубликована: Янв. 7, 2025

We report a Ni-catalyzed vicinal alkylarylation of unactivated alkenes in γ,δ- and δ,ε-alkenylamines with aryl halides alkylzinc reagents. The reaction is enabled by amine coordination can use all primary, secondary, tertiary amines. constructs two new C(sp3)-C(sp3) C(sp3)-C(sp2) bonds produces δ- ε-arylamines C(sp3)-branching at the γ- δ-positions. A variety heteroaryl iodides both primary secondary reagents be used as coupling carbon sources. Mechanistic studies suggest that cooperative effect organic nitriles electron-deficient (EDAs) ligands.

Язык: Английский

---

Transition metal catalyzed asymmetric multicomponent reactions of unsaturated compounds using organoboron reagents

Chemical Communications, Год журнала: 2020, Номер 57(4), С. 441 - 459

Опубликована: Дек. 10, 2020

Transition metal-catalyzed asymmetric multicomponent reactions using organoboron compounds have been utilized extensively for C–B, C–C, and other bond-forming reactions. This feature article highlights the important discoveries in this topic.

Язык: Английский

---