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

Angewandte Chemie, Год журнала: 2023, Номер 135(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

---

Nickel-Catalyzed 8-Aminoquinoline Directed Reductive Dialkylcyclization/Homodialkylation of Unactivated Alkenes

Organic Letters, Год журнала: 2023, Номер 25(43), С. 7800 - 7804

Опубликована: Окт. 24, 2023

Chemo and regioselective dialkylation of alkene is an efficient protocol for constructing useful chemicals, but challenges remain in the unrestricted application alkylating reagents. Alkyl bromide belongs to easy-to-access operable alkyl electrophiles that can be used reductive coupling with alkenes. Here, we reported convenient strategies dialkylcyclization homodialkylation unactivated β,γ- γ,δ-unsaturated alkenyl amides 1,3-dibromoalkanes or primary bromides under nickel-catalyzed conditions exhibited high regioselectivity functional-group tolerance.

Язык: Английский

---

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

Angewandte Chemie, Год журнала: 2023, Номер 136(5)

Опубликована: Дек. 15, 2023

Abstract 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 ‐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

---

Controllable Regiodivergent Alkynylation of 1,3‐Bis(Boronic) Esters Activated by Distinct Organometallic Reagents

Angewandte Chemie, Год журнала: 2023, Номер 135(48)

Опубликована: Окт. 18, 2023

Abstract 1,3‐Bis(boronic) esters can be readily synthesized from alkylBpin precursors. Selective transformations of these compounds hold the potential for late‐stage functionalization remaining C−B bond, leading to a diverse array molecules. Currently, there are no strategies available address reactivity and, more importantly, controllable regiodivergent 1,3‐bis(boronic) esters. In this study, we have achieved alkynylation The regioselectivity has been clarified based on unique chelation patterns observed with different organometallic reagents. Remarkably, methodology effectively addresses low and bridges gap in radical chemistry, which typically yields only classical products formed via stable intermediates. Furthermore, through approach serve as potent building blocks creating molecular diversity.

Язык: Английский

---

Precision Alkynylation of 1,3-Bis(Boronates) by Utilizing Distinct Organometallic Reagents for Regioselective Synthesis

Synlett, Год журнала: 2023, Номер 35(16), С. 1839 - 1843

Опубликована: Дек. 29, 2023

Abstract The selective functionalization of 1,3-bis(boronic) esters holds the potential for creating diverse molecular structures, particularly through late-stage remaining C–B bond. By employing distinct organometallic reagents, we have developed a method regiodivergent alkynylation esters, facilitated by unique chelation patterns. Notably, this methodology effectively overcomes limitations commonly encountered in radical chemistry, which generates only monoselective downstream targets. Furthermore, compounds synthesized approach can serve as significant building blocks, contributing to construction complexity.

Язык: Английский

---