6052-63-7Relevant academic research and scientific papers
Directed Nickel-Catalyzed Diastereoselective Reductive Difunctionalization of Alkenyl Amines
Zhao, Lei,Meng, Xiao,Zou, Yifeng,Zhao, Junsong,Wang, Lili,Zhang, Lanlan,Wang, Chao
supporting information, p. 8516 - 8521 (2021/10/25)
We report herein an intermolecular syn-arylalkylation and alkenylalkylation of alkenyl amines with two different organohalides (iodides and bromides) using Ni(II) catalyst. The cleavable bidentate quinolinamide is utilized after extensive directing group screening to enable olefin difunctionalization with high levels of regio-, chemo-, and diastereocontrol. This general and practical protocol is compatible with α- or β-substituted terminal alkenes and internal alkenes, providing rapid access to branched aliphatic amines bearing two skipped and vicinal stereocenters with high diastereoselectivities that would otherwise be difficult to synthesize.
Rhodium-Catalyzed Diverse Arylation of 2,5-Dihydrofuran: Controllable Divergent Synthesis via Four Pathways
Dou, Xiaowei,Hayashi, Tamio,Lu, Tao,Xing, Junhao,Ye, Bihai,Zhu, Wanjiang
, p. 2958 - 2963 (2020/03/23)
The rhodium-catalyzed controllable diverse arylation of 2,5-dihydrofuran with arylboronic acids is reported. By fine-tuning of the reaction conditions, four different ring-opening or oxidative arylation pathways are controlled in the rhodium-catalyzed ary
Generation and Application of (Diborylmethyl)zinc(II) Species: Access to Enantioenriched gem-Diborylalkanes by an Asymmetric Allylic Substitution
Lee, Yeosan,Park, Jinyoung,Cho, Seung Hwan
supporting information, p. 12930 - 12934 (2018/09/25)
We report the successful generation of (diborylmethyl)zinc(II) species by transmetallation beteween isolable (diborylmethyl)lithium and zinc(II) halide (X=Br, Cl) and their application in the synthesis of enantioenriched gem-diborylalkanes bearing a stereogenic center at the β-position of the diboryl groups by an asymmetric allylic substitution reaction. The reaction has a broad substrate scope, and various enantioenriched gem-diborylalkanes can be obtained in good yields with excellent enantioselectivity. Further elaboration of the enantioenriched gem-diborylalkanes provides access to a diverse set of valuable chiral building blocks.
Nickel-Catalyzed Direct Coupling of Allylic Alcohols with Organoboron Reagents
Wang, Gaonan,Gan, Yi,Liu, Yuanhong
supporting information, p. 916 - 920 (2018/09/22)
The direct coupling of allylic alcohols with arylboronic acids or their derivatives catalyzed by Ni(cod)2 in the presence of a catalytic amount of base has been developed. A wide variety of allylic substrates or arylboronic acids turned out to be applicable to this catalytic system. The present method does not require the use of ligands for stabilizing the nickel catalyst in most cases or additional activators for activation of allylic alcohols.
Total Synthesis of (-)-Chanoclavine i and an Oxygen-Substituted Ergoline Derivative
Lu, Jia-Tian,Shi, Zi-Fa,Cao, Xiao-Ping
supporting information, p. 7774 - 7782 (2017/08/14)
An efficient and direct route to ergot alkaloid (-)-chanoclavine I (3) is described using the inexpensive compound (2R)-(+)-phenyloxirane (15) as a chiral pool in 13 steps with 17% overall yield. Key features of the synthesis include a palladium-catalyzed intramolecular aminoalkynylation of terminal olefin and a rhodium-catalyzed intramolecular [3 + 2] annulation. An oxygen-substituted ergoline derivative (-)-25 was also achieved by using the same strategy.
Cross-coupling of vinylethylene carbonates with arylboronic acids catalyzed by in situ generated palladium nanoparticles in water
Mao, Yuxue,Zhai, Xing,Khan, Ajmal,Cheng, Jiong,Wu, Xue,Zhang, Yong Jian
supporting information, p. 3268 - 3271 (2016/07/11)
A practical and greener method of the cross-coupling of vinylethylene carbonates (VECs) with arylboronic acids has been described. The coupling reaction was catalyzed by in situ generated palladium nanoparticles (PdNPs) without any ligands and additional stabilizers in water under ambient conditions to provide useful 4-hydroxylprenylarenes and their derivatives in good to high yields.
Reversible C-C bond activation enables stereocontrol in Rh-catalyzed carbonylative cycloadditions of aminocyclopropanes
Shaw, Megan H.,McCreanor, Niall G.,Whittingham, William G.,Bower, John F.
supporting information, p. 463 - 468 (2015/01/30)
Upon exposure to neutral or cationic Rh(I)-catalyst systems, amino-substituted cyclopropanes undergo carbonylative cycloaddition with tethered alkenes to provide stereochemically complex N-heterocyclic scaffolds. These processes rely upon the generation and trapping of rhodacyclopentanone intermediates, which arise by regioselective, Cbz-directed insertion of Rh and CO into one of the two proximal aminocyclopropane C-C bonds. For cyclizations using cationic Rh(I)-systems, synthetic and mechanistic studies indicate that rhodacyclopentanone formation is reversible and that the alkene insertion step determines product diastereoselectivity. This regime facilitates high levels of stereocontrol with respect to substituents on the alkene tether. The option of generating rhodacyclopentanones dynamically provides a new facet to a growing area of catalysis and may find use as a (stereo)control strategy in other processes.
SnCl2/KI-mediated allylation reactions of formaldehyde in water
Lin, Mei-Huey,Lin, Long-Zhi,Chuang, Tsung-Hsun
supporting information; experimental part, p. 1871 - 1874 (2011/09/16)
An efficient procedure for SnCl2/KI-mediated allylation reactions of formaldehyde with a variety of allylic bromides in aqueous solution is reported. Under conditions developed in this effort, various homoallylic alcohols and 2-halohomoallylic alcohols are produced in good to excellent yields. Georg Thieme Verlag Stuttgart New York.
Copper-free defluorinative alkylation of allylic difluorides through Lewis acid-mediated C-F bond activation
Yanai, Hikaru,Okada, Haruna,Sato, Azusa,Okada, Midori,Taguchi, Takeo
supporting information; experimental part, p. 2997 - 3000 (2011/06/21)
The reactions of difluorohomoallyl alcohols with trialkylaluminiums smoothly proceeded in CH2Cl2 at room temperature to give (Z)-fluoro-olefin products in excellent yields. On the basis of this chemistry, fluoro-olefinic dipeptide isostere of norvalinyl glycine was synthesized in stereoselective manner.
Catalytic scaffolding ligands: An efficient strategy for directing reactions
Lightburn, Thomas E.,Dombrowski, Michael T.,Tan, Kian L.
supporting information; experimental part, p. 9210 - 9211 (2009/02/03)
The design and application of a scaffolding ligand that promotes branch and diastereoselective hydroformylation of terminal olefins as well as the regio- and diastereoselective hydroformylation of disubstituted olefins is reported. It is shown that the ligand covalently and reversibly bonds to the substrate, allowing for directed hydroformylation. As the substrate ligand interaction is dynamic, hydroformylations are catalytic in ligand and do not require any additional synthetic steps to add or remove the directing group. Using a catalytic quantity of a scaffolding ligand (20-25 mol %), excellent regioselectivity for disubstituted olefins (up to 98:2) and high branch selectivity (up to 88:12) for terminal olefins were obtained. Copyright
