FLP catalysis: main group hydrogenations of organic unsaturated substrates

Chemical Society Reviews, Год журнала: 2018, Номер 48(13), С. 3592 - 3612

Опубликована: Сен. 4, 2018

This article is focused on recent developments in main group mediated hydrogenation chemistry and catalysis using “frustrated Lewis pairs” (FLPs).

Язык: Английский

---

Diverse Uses of the Reaction of Frustrated Lewis Pair (FLP) with Hydrogen

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(48), С. 20002 - 20014

Опубликована: Ноя. 17, 2021

The articulation of the notion "frustrated Lewis pairs" (FLPs) emerged from discovery that H2 can be reversibly activated by combinations sterically encumbered main group acids and bases. This has prompted numerous studies focused on various perturbations acid/base applications to organic reductions. Perspective focuses new directions developments are emerging this FLP chemistry involving hydrogen. Three areas discussed including approaches reductions, reductions small molecules, advances in heterogeneous systems. These foci serve illustrate despite having its roots chemistry, simple concept FLPs is being applied across discipline.

Язык: Английский

---

Site‐selective Hydrogenation/Deuteration of Benzylic Olefins Enabled by Electroreduction Using Water

Chemistry - A European Journal, Год журнала: 2023, Номер 29(32)

Опубликована: Март 27, 2023

We describe an operationally simple and user-friendly protocol that allows the site-selective hydrogenation deuteration of di-, tri- tetrasubstituted benzylic olefins by electroreduction while other groups prone to are present. The radical anionic intermediates react with most inexpensive hydrogen/deuterium source H2 O/D2 O. Our method overcomes many limitations arise from previously reported electroreductive hydrogenations. applicability this reaction is demonstrated a broad substrate scope (>50 examples) focuses on functional group tolerance sites affected metal-catalyzed (alkenes, alkynes, protecting groups).

Язык: Английский

---

Boron-Catalyzed O–H Bond Insertion of α-Aryl α-Diazoesters in Water

Organic Letters, Год журнала: 2018, Номер 20(15), С. 4672 - 4676

Опубликована: Июль 23, 2018

A catalytic, metal-free O–H bond insertion of α-diazoesters in water the presence B(C6F5)3·nH2O (2 mol %) was developed, affording a series α-hydroxyesters good to excellent yields. The reaction features easy operation and wide substrate scope, importantly, no metal is needed as compared with conventional methods. Significantly, this approach further expands applications B(C6F5)3 under water-tolerant conditions.

Язык: Английский

---

B(C₆F₅)₃-Catalyzed redox-neutral β-alkylation of tertiary amines using p-quinone methides via borrowing hydrogen

Chemical Communications, Год журнала: 2018, Номер 55(9), С. 1217 - 1220

Опубликована: Дек. 21, 2018

A transition metal-free intermolecular redox-neutral β-alkylation of acyclic tertiary amines via borrowing hydrogen catalyzed by commercially available B(C₆F₅)₃ was achieved.

Язык: Английский

---

Nitrenium Salts in Lewis Acid Catalysis

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(7), С. 2715 - 2719

Опубликована: Дек. 6, 2019

Abstract Molecular compounds featuring nitrogen atoms are typically regarded as Lewis bases and extensively employed donor ligands in coordination chemistry or nucleophiles organic chemistry. By contrast, electrophilic nitrogen‐containing much rarer. Nitrenium cations a new family of nitrogen‐based acids, the reactivity which remains largely unexplored. In this work, nitrenium ions explored catalysts five transformations. These reactions first examples acid catalysis employing site substrate activation. Moreover, these readily accessed from commercially available reagents exhibit remarkable stability toward moisture, allowing for benchtop transformations without need to pretreat solvents.

Язык: Английский

---

Metal-Free Transfer Hydroiodination of C–C Multiple Bonds

Journal of the American Chemical Society, Год журнала: 2018, Номер 141(2), С. 1135 - 1140

Опубликована: Дек. 14, 2018

The design and a gram-scale synthesis of bench-stable cyclohexa-1,4-diene-based surrogate gaseous hydrogen iodide are described. By initiation with moderately strong Brønsted acid, is transferred from the onto C–C multiple bonds such as alkynes allenes without involvement free iodide. fragments into toluene ethylene, easy-to-remove volatile waste. This hydroiodination reaction avoids precarious handling or hydroiodic acid. this, broad range previously unknown difficult-to-prepare vinyl iodides can be accessed in stereocontrolled fashion.

Язык: Английский

---

FLP‐Catalyzed Transfer Hydrogenation of Silyl Enol Ethers

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(38), С. 12356 - 12359

Опубликована: Авг. 14, 2018

Abstract Herein we report the first catalytic transfer hydrogenation of silyl enol ethers. This metal free approach employs tris(pentafluorophenyl)borane and 2,2,6,6‐tetramethylpiperidine (TMP) as a commercially available FLP catalyst system naturally occurring γ‐terpinene dihydrogen surrogate. A variety ethers undergo efficient hydrogenation, with reduced products isolated in excellent yields (29 examples, 82 % average yield).

Язык: Английский

---

B(C₆F₅)₃-Catalyzed β-Functionalization of Pyrrolidines Using Isatins via Borrowing Hydrogen: Divergent Access to Substituted Pyrrolidines and Pyrroles

Organic Letters, Год журнала: 2020, Номер 22(20), С. 7797 - 7803

Опубликована: Сен. 29, 2020

We report herein a B(C6F5)3-catalyzed redox-neutral β-functionalization of pyrrolidines with isatins. Under transition-metal- and oxidant-free conditions at ambient temperature, series bearing functionalized exocyclic alkene are accessed in high efficiency through borrowing hydrogen process. A simple switch to higher reaction temperature one-pot procedure also provides access diverse array C(3)-functionalized pyrroles while liberating water gas as the only byproducts.

Язык: Английский

---

Boron-Catalyzed Azide Insertion of α-Aryl α-Diazoesters

The Journal of Organic Chemistry, Год журнала: 2019, Номер 84(7), С. 4478 - 4485

Опубликована: Март 11, 2019

A challenging metal-free azide insertion of α-aryl α-diazoesters in the presence B(C6F5)3 (5 mol %) was developed for first time. The reaction features an easy operation, wide substrate scope, and mild conditions affords corresponding products moderate to high yields. More importantly, alkene alkyne functional groups were well tolerated because no cyclopropanation or cyclopropenation observed. Furthermore, could be converted primary amines 1,2,3-triazole derivatives after simple transformations.

Язык: Английский

---