scholarly journals N-Heterocyclic olefins as ancillary ligands in catalysis: a study of their behaviour in transfer hydrogenation reactions

2016 ◽  
Vol 45 (32) ◽  
pp. 12835-12845 ◽  
Author(s):  
Amaia Iturmendi ◽  
Nestor García ◽  
E. A. Jaseer ◽  
Julen Munárriz ◽  
Pablo J. Sanz Miguel ◽  
...  
Keyword(s):  
Hydrogenation Reaction ◽  
Transfer Hydrogenation ◽  
Ancillary Ligands ◽  
Hydrogenation Reactions ◽  
Transfer Hydrogenation Reaction

Ir(i) complexes featuring an N-heterocyclic olefin ligand (NHO) have been tested in the transfer hydrogenation reaction; this representing the first example of the use of NHOs as ancillary ligands in catalysis.

Hydroxyl and ester functionalized N-heterocyclic carbene complexes of iridium(i): efficient catalysts for transfer hydrogenation reactions

RSC Advances ◽  
2014 ◽  
Vol 4 (50) ◽  
pp. 26222-26230 ◽  
Author(s):  
Derya Gülcemal ◽  
Aytaç Gürhan Gökçe ◽  
Süleyman Gülcemal ◽  
Bekir Çetinkaya
Keyword(s):  
Hydrogenation Reaction ◽  
Transfer Hydrogenation ◽  
Carbene Complexes ◽  
Aldehydes And Ketones ◽  
Hydrogenation Reactions ◽  
Transfer Hydrogenation Reaction

Iridium(i)–NHC catalyzed transfer hydrogenation reaction of aldehydes and ketones with up to 10 000 TON has been achieved.

scholarly journals Bis-NHC–Ag/Pd(OAc)2 Catalytic System Catalyzed Transfer Hydrogenation Reaction

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Hui-Ju Chen ◽  
Chien-Cheng Chiu ◽  
Tsui Wang ◽  
Dong-Sheng Lee ◽  
Ta-Jung Lu
Keyword(s):  
Functional Groups ◽  
Catalytic System ◽  
High Efficiency ◽  
Aqueous Media ◽  
Hydrogenation Reaction ◽  
Transfer Hydrogenation ◽  
Terminal Alkynes ◽  
Wide Range ◽  
Transfer Hydrogenation Reaction

The bis-NHC–Ag/Pd(OAc)2 catalytic system (NHC = N-heterocyclic carbene), a combination of bis-NHC–Ag complex and Pd(OAc)2, was found to be a smart catalyst in the Pd-catalyzed transfer hydrogenation of various functionalized arenes and internal/terminal alkynes. The catalytic system demonstrated high efficiency for the reduction of a wide range of various functional groups such as carbonyls, alkynes, olefins, and nitro groups in good to excellent yields and high chemoselectivity for the reduction of functional groups. In addition, the protocol was successfully exploited to stereoselectivity for the transformation of alkynes to alkenes in aqueous media under air. This methodology successfully provided an alternative useful protocol for reducing various functional groups and a simple operational protocol for transfer hydrogenation.

Transfer hydrogenation of cinnamaldehyde with 2-propanol on Al2O3 and SiO2–Al2O3 catalysts: role of Lewis and Brønsted acidic sites

2017 ◽  
Vol 7 (19) ◽  
pp. 4511-4519 ◽  
Author(s):  
Zhan-Kun Gao ◽  
Yong-Chun Hong ◽  
Zhun Hu ◽  
Bo-Qing Xu
Keyword(s):  
Hydrogenation Reaction ◽  
Transfer Hydrogenation ◽  
Catalytic Transfer Hydrogenation ◽  
Basic Sites ◽  
Acidic Sites ◽  
Catalytic Transfer ◽  
Transfer Hydrogenation Reaction

Neither surface Brønsted acidic nor basic sites are involved in the catalytic transfer hydrogenation reaction of cinnamaldehyde with 2-propanol.

scholarly journals Catalytic Activity of High-Surface-Area Amorphous MgO Obtained from Upsalite

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1338
Author(s):  
Marek Gliński ◽  
Ewa M. Iwanek (nee Wilczkowska) ◽  
Urszula Ulkowska ◽  
Agnieszka Czajka ◽  
Zbigniew Kaszkur
Keyword(s):  
Surface Area ◽  
Carbonyl Compounds ◽  
Main Product ◽  
High Surface ◽  
High Surface Area ◽  
Hydrogenation Reaction ◽  
Transfer Hydrogenation ◽  
Reaction Conditions ◽  
Synthesis Conditions ◽  
Transfer Hydrogenation Reaction

The first aim of the research was to synthesize a pure Upsalite, which is an amorphous form of MgCO3, by modifying a procedure described in the literature, so that it would be the precursor of a high-surface, amorphous magnesium oxide. The results indicate that within the studied reaction conditions, the type of alcohol used as the reactant has the most pronounced effect on the yield of reaction. From the two alcohols that led to the highest yield of Upsalite, methanol gave a substantially larger surface area (794 vs. 191 m2 g−1). The optimized synthesis conditions of Upsalite were used to obtain MgO via thermolysis, whose activity in the transfer hydrogenation reaction (THR) from ethanol, 2-propanol and 2-pentanol to various carbonyl compounds was determined. The optimal conditions for the thermolysis were as follows: vacuum, T = 673 K as the final temperature, and a heating rate of 2 deg min−1. The high-surface, amorphous magnesia (SBET = 488 m2 g−1) was found to be a very selective catalyst to 4-t-butylcyclohexanone in THR, which led to a diastereoselectivity of over 94% to the E-isomer of 4-t-butylcyclohexanol for more than 3 h, with conversions of up to 97% with either 2-propanol or 2-pentanol as the hydrogen donor. In the case of acrolein and 2-n-propylacrolein being used as the hydrogen acceptors, the unsaturated alcohol (UOL) was the main product of the reaction, with higher UOL yields noted for ethanol than 2-propanol.

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