2272-57-3Relevant academic research and scientific papers
Copper-Catalyzed Intermolecular Enantioselective Radical Oxidative C(sp3)?H/C(sp)?H Cross-Coupling with Rationally Designed Oxazoline-Derived N,N,P(O)-Ligands
Gu, Qiang-Shuai,Guo, Kai-Xin,Li, Zhong-Liang,Liu, Lin,Liu, Xin-Yuan,Tian, Yu,Yang, Chang-Jiang,Ye, Liu
supporting information, p. 26710 - 26717 (2021/11/18)
The intermolecular asymmetric radical oxidative C(sp3)?C(sp) cross-coupling of C(sp3)?H bonds with readily available terminal alkynes is a promising method to forge chiral C(sp3)?C(sp) bonds because of the high atom and step economy, but remains underexplored. Here, we report a copper-catalyzed asymmetric C(sp3)?C(sp) cross-coupling of (hetero)benzylic and (cyclic)allylic C?H bonds with terminal alkynes that occurs with high to excellent enantioselectivity. Critical to the success is the rational design of chiral oxazoline-derived N,N,P(O)-ligands that not only tolerate the strong oxidative conditions which are requisite for intermolecular hydrogen atom abstraction (HAA) processes but also induce the challenging enantiocontrol. Direct access to a range of synthetically useful chiral benzylic alkynes and 1,4-enynes, high site-selectivity among similar C(sp3)?H bonds, and facile synthesis of enantioenriched medicinally relevant compounds make this approach very attractive.
P-Chiral Monophosphorus Ligands for Asymmetric Copper-Catalyzed Allylic Alkylation
Xiong, Wenrui,Xu, Guangqing,Yu, Xinhong,Tang, Wenjun
, p. 4003 - 4013 (2019/06/24)
Asymmetric copper-catalyzed allylic alkylation between allyl bromides and alkyl Grignard reagents using a P-chiral monophosphorus ligand is described. A range of terminal olefins bearing tertiary or quaternary carbon centers were formed in good branched/linear selectivities and excellent enantioselectivities at copper loadings as low as 0.5 mol %.
The aldol-Grob reaction: Regioselective synthesis of (E)-alkenes from aldehydes and ketones with ytterbium triflate catalysis
Curini, Massimo,Epifano, Francesco,Maltese, Federica,Marcotullio, Maria Carla
, p. 1631 - 1634 (2007/10/03)
A simple, good yielding and solvent-free aldol-Grob reaction sequence, catalysed by Yb(OTf)3 hydrate, affording (E)-alkenes regioselectively from aldehydes and ketones is described. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Synthesis of (E)-1-Aryl-1-alkenes via a Novel BF3·OEt2-Catalyzed Aldol-Grob Reaction Sequence
Kabalka, George W.,Li, Nan-Sheng,Tejedor, David,Malladi, Rama R.,Trotman, Sarah
, p. 3157 - 3161 (2007/10/03)
The reactions of aromatic aldehydes with ketones in the presence of various acids were examined. The reactions generate (E)-1-aryl-1-alkenes in the presence of boron trifluoride diethyl etherate in nonnucleophilic solvents.
A tandem Aldol-Grob reaction of ketones with aromatic aldehydes
Kabalka, George W.,Tejedor, David,Li, Nan-Sheng,Malladi, Rama R.,Trotman, Sarah
, p. 15525 - 15532 (2007/10/03)
Aromatic aldehydes react with ketones to produce (E)-1-aryl-1-alkenesvia a tandem Aldol-Grob cleavage reaction sequence. The reaction, initiated by boron trifluoride, also produces a carboxylic acid fragment.
Protonation and Alkykation of 1-Arylpropenyl-lithium
Tanaka, Jiro,Nojima, Masatomo,Kusabayashi, Shigekazu,Nagase, Shigeru
, p. 673 - 678 (2007/10/02)
The protonation and alkylation of 1-arylpropenyl-lithium (1a-c) in ether was undertaken systematically; the regio- and stereo-chemistry being influenced by various factors.The characteristic features are as follows. (a) Protonation occurs predominantly at C-3, whereas the sterically more crowded C-1 is the more favoured site for alkylation, and (b) although 1-arylpropenyl-lithium (1) seems to exist mainly as the E-isomer, in some cases the product (3) or (5) having the Z-configuration is produced from attack at C-3 in a significant amount together with the E-isomer, e.g. protonation by oxygen acids in the presence or absence of tetramethylethylenediamine and methylation of the p-methoxy derivative (1a).
