ClimateTech
Material Science
Green Catalytic Formation of Alcohols, Amines, Amides, Imines and Esters under Mild Conditions (No. T4-1551)

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Overview

In recent years, complexes based on cooperating ligands have exhibited remarkable catalytic activity. These ligands can cooperate with the metal center by undergoing reversible structural
changes in the processes of substrate activation and product formation.
Prof. David Milstein's group has discovered a new mode of action for metal-ligand cooperation, involving aromatization, and dearomatization of ligands. Pincer-type, pyridine-based complexes of Mn
and acridine complexes of Ru have been shown to exhibit such cooperation, leading to facile activation of C-H, CC, H-H, N-H, and O-H bonds.

The Need

Amines, alcohols, amides, imines, and esters, are essential for industries such as research, chemicals, plastics and polymers, dyes, fragrances, fibers, pharmaceuticals, and agrochemicals. However, require conditions of high temperature/pressure and stoichiometric amounts of different hazardous compounds (e.g. activated acid derivatives or large amounts of metal compounds) to synthesize.

Carbon-carbon bond formation reactions are of fundamental importance in organic chemistry. Yet, they often require the application of strong bases, which may not be compatible with various functional groups and can lead to undesired side reactions.

In addition, there is a strong interest in the replacement of noble metal catalysts by more economical and environmentally friendly catalysts, based on earth-abundant metals. Further there is a need for cheaper and more efficient synthetic methods.

The Solution

A novel set of catalysts based on manganese, ruthenium, and related borohydride complexes (Pincer-type) gives an alternative green option in synthesizing fundamental compounds.

Technology Essence

In recent years, complexes based on “cooperating” ligands have exhibited remarkable catalytic activity. These ligands can cooperate with the metal center by undergoing reversible structural changes in the processes of substrate activation and product formation.

Prof. David Milstein’s group has discovered a new mode of action for metal-ligand cooperation, involving aromatization–dearomatization of ligands. Pincer-type, pyridine-based complexes of Mn and acridine complexes of Ru have been shown to exhibit such cooperation, leading to facile activation of C-H, C-C, H-H, N-H, and O-H bonds.

Applications and Advantages

Advantages

  • Reduced material cost (cheaper catalysts & reagents, reduced need for protecting groups, fewer reaction steps, higher yields, and less work-up.)
  • Lower waste treatment cost (catalytic amounts - 1% mol, absence of toxic reagents, and byproducts, minimizes hazardous waste formation.)
  • Decreased energy costs (Mild conditions - pressure 10 atm, temperatures of ~110 Co)
  • No additives (just substrates and catalyst, except with certain reactions where hydrogen is required)
  • New synthetic pathways that were not feasible before (e.g. such as the synthesis of amides and imines directly from alcohols and amines, esters synthesis from alcohols)
  • Broad substrate scope and excellent yields

 
Applications

  • Pharmaceuticals
  • Dyes
  • Cosmetics and fragrances
  • Fibers
  • Agrochemicals
Development Status

The novel catalysts have been used in the following reactions:

Patent Status: 
European Patent Office Published: Publication Number: 4402120 USA Granted: 10,533,028 USA Granted: 11,731,116 USA Granted: 9,045,381
Extension Service David Milstein

David Milstein

Faculty of Chemistry
Molecular Chemistry and Materials Science
All projects (3)
Contact for more information

Dr. Vered Pardo Yissar

Director of Business Development, Exact Sciences

+972-8-9342666 Linkedin