C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material sciences, crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these C–H functionalizations required precious 4d or 5d transition metal catalysts. Given the cost-effective and sustainable nature of earth-abundant first row transition metals, the development of less toxic, inexpensive 3d metal catalysts for C–H activation has gained considerable recent momentum as a significantly more environmentally-benign and economically-attractive alternative. Herein, we provide a comprehensive overview on first row transition metal catalysts for C–H activation until summer 2018.

3d Transition Metals for C-H Activation.

Transition metal-catalysed C–H activation has emerged as an increasingly powerful platform for molecular syntheses, enabling applications to natural product syntheses, late-stage modification, pharmaceutical industries and material sciences, among others. This Primer summarizes representative best practices for the experimental set-up and data deposition for C–H activation, as well as discussing key developments including recent advances in asymmetric, photoinduced and electrocatalytic C–H activation. Likewise, strategies for applications of C–H activation towards the assembly of structurally complex (bio)polymers and drugs in academia and industry are discussed. In addition, current limitations in C–H activation and possible approaches for overcoming these shortcomings are reviewed. This Primer provides an overview of the best practices for C–H activation as well as key advances in asymmetric, photoinduced and electrocatalytic-mediated catalysis for this synthetic platform. An overview of how C–H activation facilitates the synthesis of molecules such as structurally complex (bio)polymers and drugs is provided along with the current challenges and priorities for the next decade.

C–H activation

This review serves to document advances in the synthesis, versatile bonding, and reactivity of molecular main group metal hydrides within Groups 1, 2, and 12-16. Particular attention will be given to the emerging use of said hydrides in the rapidly expanding field of Main Group element-mediated catalysis. While this review is comprehensive in nature, focus will be given to research appearing in the open literature since 2001.

Molecular Main Group Metal Hydrides

Metallo-photoredox catalysis has redefined the available bond disconnections in the synthetic arsenal. By harnessing the one-electron chemistry of photoredox catalysis in tandem with low-valent cobalt catalysts, new methods by which functionalities may be stitched together become available. Herein we describe the coupling of photoredox-generated α-amino radical species with conjugated dienes using a unified cobalt and iridium catalytic system in order to access a variety of useful homoallylic amines from simple commercially available starting materials. We present a series of mechanistic experiments that support the intervention of Co–hydride intermediates that undergo diene insertion to generate Co−π-allyl species.

A Mild Hydroaminoalkylation of Conjugated Dienes Using a Unified Cobalt and Photoredox Catalytic System.

https://iopscience.iop.org/article/10.1070/RCR4795/pdf

Organofluorine chemistry: promising growth areas and challenges

A homoleptic scandium trialkyl complex in combination with a borate compound served as an excellent catalyst for the C–H addition of aliphatic tertiary amines to olefins. This highly regiospecific, 100% atom efficient C–H bond alkylation reaction was applicable to a wide variety of tertiary amines and olefins, including functionalised styrenes and unactivated α-olefins. This work represents the first example of rare-earth catalysed olefin hydroaminoalkylation and also the first example of catalytic C–H addition of aliphatic tertiary amines to olefins with any catalyst.

/pdf/scandium-catalysed-intermolecular-hydroaminoalkylation-of-adp81em5fn.pdf

Scandium-catalysed intermolecular hydroaminoalkylation of olefins with aliphatic tertiary amines.

Weakly Coordinated Zinc and Aluminum σ-Complexes of Copper(I)

Group IV metal complexes have previously shown promise as novel anticancer agents. Here, we discuss the mechanistic and cytotoxic nature of a series of group IV β-diketonate coordination complexes. Clear evidence that the ligands are exchangeable on the metal centre and that the β-diketonate ligands can act as potential drug delivery vehicles of the group IV metal ions was obtained. When evaluated for the cytotoxicity against human colon adenocarcinoma (HT-29) and human breast adenocarcinoma (MCF-7) cell lines, a general trend of decreasing potency down the group IV metals was observed. The most promising results obtained were for the hafnium complexes, with the tris diphenyl β-diketonate hafnium complex exhibiting IC50 values of 4.9 ± 0.9 μM and 3.2 ± 0.3 μM against HT-29 and MCF-7, respectively, which are comparable with the activity of cisplatin against the same cell lines. This tri β-diketonate hafnium complex is the first to show potent in vitro cytotoxic activity. The results reported show that ligand design has a significant effect on the cytotoxic potential of the complexes, and that these group IV complexes warrant further evaluation as novel metal-containing anticancer agents.

Mechanistic and Cytotoxicity Studies of Group IV β‐Diketonate Complexes

A series of bis(σ-B–H) complexes of copper(I) have been prepared by displacement of arene solvent from a β-diketiminate copper(I) complex by four-coordinate boranes, H3B–L (L = NMe3, lutidine). In the presence of the same copper arene complex, the secondary amine–borane H3B–NMe2H undergoes dehydrogenation. We provide evidence for formation of a heterogengous catalyst from decomposition of the solution species.

/pdf/bis-s-b-h-complexes-of-copper-i-precursors-to-a-ky3h1n893a.pdf

Bis(σ-B–H) complexes of copper(I): precursors to a heterogeneous amine–borane dehydrogenation catalyst

The synthesis of a diverse series of hydride complexes of aluminium coordinated by N,N′-chelating ligands is reported. Reaction of [{2,6-iPr2C6H3}NC(Me)CHC(Me)N(H)CH2CH2NMe2] with either LiAlH4 or Me3N·AlH3 allows isolation of the corresponding five-coordinate aluminium dihydride [κ3-{(2,6-iPr2C6H3)NC(Me)CHC(Me)NCH2CH2NMe2}AlH2] (2). The latter complex demonstrates trigonal bipyramidal geometry in the solid-state. Correlation of solid and n-hexane solution infrared spectroscopy data reveals that this coordination is retained in solution. To evaluate the observed coordination geometry, the dissociation of the pendant ligand of 2 was investigated by DFT methods conducted with the M06-2X functional and a hybrid 6,31G+(d,p)/Lanl2DZ basis-set. Reaction of Me3N·AlH3 with both N,N′-bis(di-iso-propylphenyl)ethylenediamine and N,N′-bis(mesityl)ethylenediamine gave [{κ2-(ArNCH2)2}AlH(NMe3)] (Ar = Mes, 3a; Ar = 2,6-di-iso-propylphenyl, 3b) in moderate yields. Removal of NMe3 from 3b by heating under dynamic vacuum allowed the isolation of cis-[AlH{μ-N(Ar)CH2CH2N(Ar)}] (Ar = 2,6-di-iso-propylphenyl, cis-4b22) as a single diastereomer following crystallization. DFT studies in combination with infrared and NMR spectroscopy and single crystal X-ray diffraction data provide a weight of evidence consistent with the robust dimeric structure of cis-4b22 remaining intact in solution. An unusual reaction in which the aluminium dihydride, [κ2-{(2,6-Me2C6H3NHCH2)2CH}AlH2], promotes the P–C bond cleavage of Ph3PCH2 is also reported.

/pdf/preparation-and-properties-of-a-series-of-structurally-udikfq4t4u.pdf

Preparation and properties of a series of structurally diverse aluminium hydrides supported by β-diketiminate and bis(amide) ligands

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Adi E. Nako

Author Tools

Chat about Author