28811-80-5Relevant academic research and scientific papers
Cobalt-Catalyzed Asymmetric 1,4-Reduction of β,β-Dialkyl α,β-Unsaturated Esters with PMHS
Lu, Dongpo,Lu, Peng,Lu, Zhan
supporting information, p. 4861 - 4864 (2021/09/22)
A cobalt-catalyzed asymmetric reduction of β,β-dialkyl α,β-unsaturated esters with polymethylhydrosiloxane (PMHS) was reported to deliver the corresponding esters containing a chiral trialkyl carbon center at β-position with up to 97 % yield and 98 % ee. The chiral tridentate ligand oxazoline iminopyridine (OIP) could perform well for the asymmetric reduction instead of chiral bidentate ligands. This operationally simple protocol shows a broad scope of substrates using one equivalent of readily available PMHS as a cheap and easy-to-handle reductive reagent.
Mild and Selective Rhodium-Catalyzed Transfer Hydrogenation of Functionalized Arenes
Wang, Yuhan,Chang, Zhiqian,Hu, Yan,Lin, Xiao,Dou, Xiaowei
supporting information, p. 1910 - 1914 (2021/03/08)
Diboron-mediated rhodium-catalyzed transfer hydrogenation of functionalized arenes is reported. In addition to good functional group tolerance, the reaction features operational simplicity and controllable chemoselectivity. The general applicability of this procedure is demonstrated by the selective hydrogenation of a range of arenes, including functionalized benzenes, biphenyls, and polyaromatics.
Catalytic hydrogenation of α,β-unsaturated carboxylic acid derivatives using copper(i)/N-heterocyclic carbene complexes
Zimmermann, Birte M.,Kobosil, Sarah C. K.,Teichert, Johannes F.
, p. 2293 - 2296 (2019/02/27)
A simple and air-stable copper(i)/N-heterocyclic carbene complex enables the catalytic hydrogenation of enoates and enamides, hitherto unreactive substrates employing homogeneous copper catalysis and H2 as a terminal reducing agent. This atom economic transformation replaces commonly employed hydrosilanes and can also be carried out in an asymmetric fashion.
Hypervalent iodine(III) catalyzed radical hydroacylation of chiral alkylidenemalonates with aliphatic aldehydes under photolysis
Selvakumar, Sermadurai,Kang, Qi-Kai,Arumugam, Natarajan,Almansour, Abdulrahman I.,Kumar, Raju Suresh,Maruoka, Keiji
, p. 5841 - 5846 (2017/09/09)
Hypervalent iodine(III) catalyzed diastereoselective radical hydroacylation of alkylidenemalonates bearing (?)-8-phenylmenthol as a chiral auxiliary with aliphatic aldehydes is realized under photolysis. This work represent the first example of diastereoselective addition of acyl radicals to olefins to afford chiral ketones in a highly stereoselective fashion. The reaction is initiated by the photolysis of hypervalent iodine(III) catalyst under mild and metal-free conditions. The synthetic potential of this methodology was demonstrated by the short formal synthesis of (?)-methyleneolactocin.
Hydroalkylation of Alkenes Using Alkyl Iodides and Hantzsch Ester under Palladium/Light System
Sumino, Shuhei,Ryu, Ilhyong
supporting information, p. 52 - 55 (2016/01/12)
The hydroalkylation of alkenes using alkyl iodides with Hantzsch ester as a hydrogen source occurred smoothly under a Pd/light system, in a novel, tin-free Giese reaction. A chemoselective reaction at C(sp3)-I in the presence of a C(sp2)-X (X = Br or I) bond was attained, which allowed for the stepwise functionalization of two types of C-X bonds in a one-pot procedure.
Highly enantioselective iridium-catalyzed hydrogenation of α,β-unsaturated esters
Li, Jia-Qi,Quan, Xu,Andersson, Pher G.
, p. 10609 - 10616 (2012/11/07)
α,β-Unsaturated esters have been employed as substrates in iridium-catalyzed asymmetric hydrogenation. Full conversions and good to excellent enantioselectivities (up to 99 % ee) were obtained for a broad range of substrates with both aromatic- and aliphatic substituents on the prochiral carbon. The hydrogenated products are highly useful as building blocks in the synthesis of a variety of natural products and pharmaceuticals. Asymmetric hydrogenation: A variety of α,β-unsaturated esters were hydrogenated with high enantioselectivities (see scheme). The hydrogenated products have been used in synthetic transformations as well as in formal total syntheses. Copyright
Indium/copper-mediated conjugate addition of unactivated alkyl iodides to α,β-unsaturated carbonyl compounds in water
Shen, Zhi-Liang,Cheong, Hao-Lun,Loh, Teck-Peng
supporting information; scheme or table, p. 1051 - 1054 (2009/05/27)
An efficient method for the conjugate addition of unactivated alkyl iodides to α,β-unsaturated carbonyl compounds using indium/copper in water is described. The reactions proceed more efficiently in water than in organic solvents. In, CuI, and InCl3
Asymmetric 1,4-reductions of and 1,4-additions to enoates and related systems
-
, (2008/06/13)
One aspect of the present invention relates to methods for the transition-metal-catalyzed asymmetric 1,4-addition of a nucleophile, e.g., hydride, to cyclic and acyclic enoates and enones. In certain embodiments of the methods of the present invention, th
A new convenient procedure to prepare organomanganese reagents from organic halides and activated manganese
Cahiez, Gerard,Martin, Arnaud,Delacroix, Thomas
, p. 6407 - 6410 (2007/10/03)
A new method to obtain activated manganese metal, especially attractive for large scale preparative organic chemistry, is described. The key point is the use of 2-phenylpyridine as electron carrier to reduce manganese chloride by lithium. The active manganese thus obtained was used to prepare various organomanganese reagents from organic halides. The reactivity of these reagents has been studied (acylation, 1,2- or 1,4-addition, alkylation and alkenylation).
