Cobalt(III) Complexes as Bifunctional Hydrogen‐Bond Donor Catalysts Featuring Halide Anions for Cyclic Carbonate Synthesis at Ambient Temperature and Pressure: A Mechanistic Insight

Cobalt(III) Complexes as Bifunctional Hydrogen‐Bond Donor Catalysts Featuring Halide Anions for Cyclic Carbonate Synthesis at Ambient Temperature and Pressure: A Mechanistic Insight Full article

Journal

Asian Journal of Organic Chemistry
ISSN: 2193-5815 , E-ISSN: 2193-5807

Output data

Year: 2022, Volume: 11, Number: 5, Article number : e202100811, Pages count : DOI: 10.1002/ajoc.202100811

Authors

Emelyanov Mikhail A. ¹ , Lisov Alexey A. ^2,3 , Medvedev Michael G. ³ , Maleev Victor I. ¹ , Larionov Vladimir A. ^4,5

Affiliations

1	A N Nesmeyanov Institute of Organoelement Compounds RAS: Institut elementoorganiceskih soedinenij imeni A N Nesmeanova RAN LAC Vavilov Str. 28 119991 Moscow RUSSIAN FEDERATION
2	Department of Chemistry Lomonosov Moscow State University, Leninskie Gory 1/3 119991 Moscow Russian Federation
3	N.D. Zelinsky Institute of Organic Chemistry of Russian Academy of Sciences Leninsky prospect 47 119991 Moscow Russian Federation
4	A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences Vavilov Str. 28 119991 Moscow Russian Federation
5	Peoples' Friendship University of Russia (RUDN University) Miklukho-Maklaya Str. 6 117198 Moscow Russian Federation

The metal-templated hydrogen bond donors (HBD) are prospective catalytic systems for the activation of organic molecules in chemical reactions. Here we report the application of the chiral cationic Co(III) complexes based on commercially available (S,S)-1,2-diaminocyclohexane and (R,R)-1,2-diphenylethylendiamine and salicylaldehydes with an iodide counter-anion as bifunctional one-component hydrogen bond donor/nucleophilic catalysts for the conversion of carbon dioxide with epoxides into valuable cyclic carbonates under solvent- and co-catalyst free conditions. We demonstrated that (R,R)-1,2-diphenylethylendiamine based complex Λ(R,R)-2 is superior to (S,S)-1,2-diaminocyclohexane based Δ(S,S)-1 a catalyzing the reaction at ambient conditions (RT and 1 bar CO2). The TON and TOF values of 850 and 35 h−1, respectively, were achieved at low catalyst loading (0.1 mol %) at 10 bars of CO2 and 100 °C. Furthermore, the Co(III) complexes catalyzed the reaction with diluted air/CO2 mixture (15 vol % of CO2) producing the desired styrene carbonate in up to 75% yield. A plausible catalytic cycle consistent with all experimental observations was proposed based on DFT calculations. The DFT calculations elucidated the difference in the ring opening step in cases of propylene oxide and styrene oxide. In addition, the kinetic resolution of terminal epoxides was observed with selectivity factor (s) of up to 1.6 in case of the complex Λ(R,R)-2.

Emelyanov M.A. , Lisov A.A. , Medvedev M.G. , Maleev V.I. , Larionov V.A.
Cobalt(III) Complexes as Bifunctional Hydrogen‐Bond Donor Catalysts Featuring Halide Anions for Cyclic Carbonate Synthesis at Ambient Temperature and Pressure: A Mechanistic Insight
Asian Journal of Organic Chemistry. 2022. V.11. N5. e202100811 . DOI: 10.1002/ajoc.202100811 WOS Scopus OpenAlex

≡ Web of science:	WOS:000771874200001
≡ Scopus:	2-s2.0-85126876402
≡ OpenAlex:	W4213426861