36941-00-1Relevant academic research and scientific papers
Highly Selective Hydrogenation of C═C Bonds Catalyzed by a Rhodium Hydride
Gu, Yiting,Lisnyak, Vladislav G.,Norton, Jack R.,Salahi, Farbod,Snyder, Scott A.,Zhou, Zhiyao
supporting information, p. 9657 - 9663 (2021/07/19)
Under mild conditions (room temperature, 80 psi of H2) Cp*Rh(2-(2-pyridyl)phenyl)H catalyzes the selective hydrogenation of the C═C bond in α,β-unsaturated carbonyl compounds, including natural product precursors with bulky substituents in the β position and substrates possessing an array of additional functional groups. It also catalyzes the hydrogenation of many isolated double bonds. Mechanistic studies reveal that no radical intermediates are involved, and the catalyst appears to be homogeneous, thereby affording important complementarity to existing protocols for similar hydrogenation processes.
Pentamethylphenyl (Ph*) and Related Derivatives as Useful Acyl Protecting Groups for Organic Synthesis: A Preliminary Study
Cheong, Choon Boon,Frost, James R.,Donohoe, Timothy J.
supporting information, p. 1828 - 1832 (2020/10/06)
A study of acyl protecting groups derived from the Ph? motif is reported. While initial studies indicated that a variety of functional groups were not compatible with the Br 2-mediated cleavage conditions required to release the Ph? group, strategies involving the use of different reagents or a modification of Ph? itself (Ph*OH) were investigated to solve this problem.
Methanol as hydrogen source: Chemoselective transfer hydrogenation of α,β-unsaturated ketones with a rhodacycle
Aboo, Ahmed H.,Begum, Robina,Zhao, Liangliang,Farooqi, Zahoor H.,Xiao, Jianliang
, p. 1795 - 1799 (2019/11/11)
Methanol is a safe, economic and easy-to-handle hydrogen source. It has rarely been used in transfer hydrogenation reactions, however. We herein report that a cyclometalated rhodium complex, rhodacycle, catalyzes highly chemoselective hydrogenation of α,β-unsaturated ketones with methanol as the hydrogen source. A wide variety of chalcones, styryl methyl ketones and vinyl methyl ketones, including sterically demanding ones, were reduced to the saturated ketones in refluxing methanol in a short reaction time, with no need for inter gas protection, and no reduction of the carbonyl moieties was observed. The catalysis described provides a practically easy and operationally safe method for the reduction of olefinic bonds in α,β-unsaturated ketone compounds.
Transition-Metal-Free Highly Chemoselective and Stereoselective Reduction with Se/DMF/H2O System
Li, Hong-Chen,An, Cui,Wu, Ge,Li, Guo-Xing,Huang, Xiao-Bo,Gao, Wen-Xia,Ding, Jin-Chang,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
supporting information, p. 5573 - 5577 (2018/09/12)
A novel metal-free reduction system, in which H2Se (or HSe-) produced in situ from Se/DMF/H2O acts as the active reducing species, has been developed. By using water as an inexpensive, safe, and environmentally friendly surrogate as the hydrogen donor, this new reduction system incorporating Se/DMF/H2O displayed high selectivity and good activity in the reduction of α,β-unsaturated ketones and alkynes. Therefore, this reduction system has great potential to be a general and practical reduction methodology in organic transformation.
Organocatalyzed biomimetic selective reduction of c=c double bonds of chalcones
Tripathi, Vishwa Deepak,Jha, Anand Mohan
, p. 2322 - 2324 (2018/09/09)
In this article, we reported a biomimetic approach for chemoselective reduction of C=C double bonds in chalcones under metal and acid free conditions, that relies on olefin activation by hydrogen bond formation. The process requires only catalytic amount of ephedrine as hydrogen bond donor and utilizes Hantzsch esters for transfer hydrogenation.
An efficient heterogenized palladium catalyst for N-alkylation of amines and α-alkylation of ketones using alcohols
Dang, Tuan Thanh,Shan, Siah Pei,Ramalingam, Balamurugan,Seayad, Abdul Majeed
, p. 42399 - 42406 (2015/05/20)
A silica supported palladium-NiXantphos complex is reported as an efficient and a high turnover heterogeneous catalyst for the N-alkylation of amines and the α-alkylation of ketones using readily available alcohols under neat conditions at 120-140 °C following hydrogen borrowing strategy. The catalyst is easily separable and offers negligible amount of palladium leaching (0.01 ppm). A high turnover number of about 46000 for the N-alkylation of amines and 4400 for the α-alkylation of ketones were achieved in the respective single batch reactions. The catalyst is recyclable up to four times without appreciable change in catalytic performance.
Palladium on graphene: The in situ generation of a catalyst for the chemoselective reduction of α,β-unsaturated carbonyl compounds
Morimoto, Naoki,Yamamoto, Shun-Ichi,Takeuchi, Yasuo,Nishina, Yuta
, p. 15608 - 15612 (2013/09/12)
Palladium-supported graphene oxide has been successfully applied as a catalyst precursor for the selective reduction of α,β-unsaturated carbonyl compounds. Pd nanoparticles were formed during the course of the reduction with only negligible leaching of the Pd species into the reaction mixture.
An improved synthesis of hydroxy aryl ketones by fries rearrangement with methanesulfonic acid/methanesulfonic anhydride
Jeon, Ingyu,Mangion, Ian K.
experimental part, p. 1927 - 1930 (2012/10/08)
Methanesulfonic acid treated with methanesulfonic anhydride effectively mediates the Fries rearrangement of aryl esters to give hydroxy aryl ketones with high yields. Georg Thieme Verlag Stuttgart · New York.
Synthesis of a series of novel 2,4,5-trisubstituted selenazole compounds as potential PLTP inhibitors
Ling, Cui,Zheng, Zhibing,Jiang, Xian Cheng,Zhong, Wu,Li, Song
scheme or table, p. 5123 - 5125 (2010/10/19)
Based on a homology-modeled structure of PLTP and characteristic structural features of reported cholesteryl ester transfer protein (CETP) inhibitors, we designed and synthesized a novel series of 2,4,5-trisubstituted selenazole compounds. Biological evaluation reveals that compounds 12 and 17 exhibit favorable PLTP activity, and their IC50s are 8 μM and 10 μM, respectively.
Direct acylation of aryl chlorides with aldehydes by palladium-pyrrolidine Co-catalysis
Colbon, Paul,Ruan, Jiwu,Purdie, Mark,Xiao, Jianliang
supporting information; experimental part, p. 3670 - 3673 (2010/10/20)
A palladium catalyst system has been developed that allows for the direct acylation of aryl chlorides with aldehydes. The choice of ligand, as well as the presence of pyrrolidine and molecular sieves is shown to be critical to the catalysis, which appears to proceed via an enamine intermediate. The reaction was successful for a wide range of aryl chlorides and tolerant of functionality on the aldehyde component, giving easy access to alkyl aryl ketones in modest to good yields.
