Synthesis of Atropisomeric Hydrazides by One‐Pot Sequential Enantio‐ and Diastereoselective Catalysis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(42)

Опубликована: Авг. 29, 2022

The first catalytic enantioselective and diastereoselective synthesis of atropisomeric hydrazides was achieved using a sequential catalysis protocol. This strategy is based on one-pot sequence two organocatalytic cycles featuring the enamine amination branched aldehydes followed by nitrogen alkylation under phase-transfer conditions. resulting axially chiral were obtained directly from commercially available reagents in high yields with good stereocontrol. permutation organocatalysts allowed easy access to all stereoisomers, enabling stereodivergent approach enantioenriched hydrazides.

Язык: Английский

---

Accelerated Direct Hydroxylation of Aryl Chlorides with Water to Phenols via the Proximity Effect in a Heterogeneous Metallaphotocatalyst

ACS Catalysis, Год журнала: 2022, Номер 12(10), С. 6068 - 6080

Опубликована: Май 6, 2022

The proximity of different active sites in multi-catalytic systems is crucial influencing the catalytic reactions, that is, to occur or be accelerated. Here, we reported a heterogeneous metallaphotocatalyst prepared by embedding Ni(II) species photosensitive covalent organic framework (COF). A concerted triad behavior executed electrons, holes, and Ni triggered dramatic enhancement activation aryl chlorides with water phenols. It demonstrated 50-fold increment its activity when compared homogeneous analogy, for example, Ni(BPDA)Br2. Also, it was able efficiently activate variety corresponding phenols moderate high yields. Interestingly, effective even base-sensitive substituents chlorobenzene bearing NH NH2 groups. On basis detailed experiments, photoactive COF facilitates rapid electron transfer produce Ni(I) oxidative addition. Meanwhile, photogenerated holes oxidized hydroxyl radical, which then attacked Ni(III) intermediates complete cycle.

Язык: Английский

---

C–C Bond Forming Reactions Enabled by Vitamin B₁₂─Opportunities and Challenges

ACS Catalysis, Год журнала: 2022, Номер 12(11), С. 6517 - 6531

Опубликована: Май 17, 2022

Cobalt not only is an essential micronutrient for mammals but also marks itself as important in organic synthesis, especially the field of catalysis. Various useful reactions, such alkene hydroformylation, hydrogenation, heterofunctionalizations carbon–carbon double bonds, C–H activation, and cross-coupling have been realized with aid this metal. At same time, cobalt deserves special attention a catalyst radical processes; fact, form vitamin B12, it was designed by Nature reversible carrier radicals. Since molecule native Co-complex, very attractive development sustainable transformations, has already demonstrated that B12 its derivatives mediate numerous reactions found applications both construction complex molecules degradation polyhalogenated pollutants. However, Perspective, we focus readers' on C–C bond forming catalyzed which are particularly tool synthesis greener manner. We ponder over challenges remain to be addressed solutions expected come.

Язык: Английский

---

Recent developments in one-pot stepwise synthesis (OPSS) of small molecules

iScience, Год журнала: 2022, Номер 25(9), С. 105005 - 105005

Опубликована: Авг. 28, 2022

One-pot synthesis is an active topic in organic chemistry due to its intrinsic advantages of simple operation, high mass efficiency, low cost, and less amount waste disposal. Among three kinds one-pot syntheses, 1) cascade reactions, 2) multicomponent reactions (MCRs), 3) stepwise (OPSS), OPSS could be more flexible practical since it carried out stepwisely have variable reaction conditions for different steps. This perspective article uses selected examples highlight the recent development involving cyclization, cycloaddition, rearrangement, catalytic heterocyclic scaffolds, asymmetric molecules, natural products, bioactive compounds.

Язык: Английский

---

Stereodivergent Construction of Csp³−Csp³Bonds Bearing Vicinal Stereocenters by Synergistic Palladium and Phase‐Transfer Catalysis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(2)

Опубликована: Ноя. 16, 2022

Abstract Synergistic catalysis has emerged as one of the most powerful tools for stereodivergent formation Csp 3 −Csp bonds bearing vicinal stereocenters. Despite many successes that have been achieved in this field, coupling reactions involving stabilized nucleophiles remain challenging because competing single‐catalysis pathway. Herein, we report a synergistic palladium/phase‐transfer catalyst system enables diastereodivergent 1,3‐dienes with nucleophile oxindoles. Both syn and anti products, quaternary tertiary stereocenters, could be selectively produced good yields high enantio‐ diastereoselectivities. Non‐covalent activation via chiral ion pair biphasic is crucial success factor achieving diastereodivergence.

Язык: Английский

---