Phenanthroline based pincer complexes useful as catalysts for the preparation of methanol from carbondioxide

• US 10,449,529 B2
• Filed: 02/10/2016
• Issued: 10/22/2019
• Est. Priority Date: 02/10/2015
• Status: Active Grant

• Current Assignee: Council of Scientific & Industrial Research
• Original Assignee: Council of Scientific & Industrial Research
• Inventors: Balaraman, Ekambaram, Landge, Vinod Gokulkrishna, Midya, Siba Prasad, Sahoo, Manoj Kumar, Jaiswal, Garima
• Primary Examiner(s): Qian, Yun
• Application Number:
  US15/549,827
• Publication Number:
  US 20180021766A1
• Time in Patent Office: 1,350 Days
• Field of Search: None
• CPC Class Codes: B01J 2231/643 of R2C=O or R2C=NR (R= C, H)
• CPC Class Codes: B01J 2231/648 Fischer-Tropsch-type reactions
• CPC Class Codes: B01J 2231/763 of -CH-XH (X= O, NH/N, S) to -C=X or -CX triple bond species
• CPC Class Codes: B01J 2531/0244 Pincer-type complexes, i.e. consisting of a tridentate skeleton bound to a metal, e.g. by one to three metal-carbon sigma-bonds
• CPC Class Codes: B01J 2531/821 Ruthenium
• CPC Class Codes: B01J 31/1815 with more than one complexing nitrogen atom, e.g. bipyridyl, 2-aminopyridine
• CPC Class Codes: B01J 31/183 with more than one complexing nitrogen atom, e.g. phenanthroline
• CPC Class Codes: B01J 31/189 containing both nitrogen and phosphorus as complexing atoms, including e.g. phosphino moieties, in one at least bidentate or bridging ligand
• CPC Class Codes: B01J 31/20 Carbonyls
• CPC Class Codes: B01J 31/2404 Cyclic ligands, including e.g. non-condensed polycyclic ligands, the phosphine-P atom being a ring member or a substituent on the ring
• CPC Class Codes: B01J 31/2447 and phosphine-P atoms as substituents on a ring of the condensed system or on a further attached ring
• CPC Class Codes: C07F 15/0046 Ruthenium compounds

Abstract

The present invention relates to a novel phenonthroline based pincer complexes and process for preparation thereof. The present invention also provides a one pot process for the conversion of carbon dioxide to methanol in the presence of a molecularly defined pincer-type single-site Ru-catalyst and secondary amine. Further the present invention provides the use of phenonthroline based pincer complexes for the esterification of alcohols and hydrogenation of esters under mild conditions.

Claims

1. A phenanthroline pincer complex, wherein said complex is selected from HCl(CO)Ru(Phen-(tBu)PNN) (3), H(CO)Ru-(Phen-(tBu)PNN (4) and H(CO)Ru(η

1BH4)(Phen-(tBu)PNN) (5).

2. The phenanthroline pincer complex as claimed in claim 1, wherein said complex is used as a catalyst for hydrogenation of lactones to diols and esters to alcohols.

3. The phenanthroline pincer complex as claimed in claim 2, wherein said catalyst is used for dehydrogenation of diols to lactones, alcohol to esters and secondary alcohols to ketones.

4. A process for the preparation of a phenanthroline pincer complex comprising the steps of:

a) adding solution of Lithium diisopropylamide and tBuOK in suitable solvent to a solution of 2-methyl-1,10-phenanthroline (1) in ether at a temperature in a range of 0°

to 5°

C. followed by stirring the reaction mixture for a period in a range of 30 to 40 minutes to obtain a solution;

5. The process as claimed in claim 4, wherein the solvent used in step (a) is selected from hexane, heptane, tetrahydrofuran (THF), diethyl ether, toluene, and etheylbenzene.