- Asymmetric Markovnikov Hydroaminocarbonylation of Alkenes Enabled by Palladium-Monodentate Phosphoramidite Catalysis
-
A palladium-catalyzed asymmetric Markovnikov hydroaminocarbonylation of alkenes with anilines has been developed for the atom-economical synthesis of 2-substituted propanamides bearing an α-stereocenter. A novel phosphoramidite ligand L16 was discovered which exhibited very high reactivity and selectivity in the reaction. This asymmetric Markovnikov hydroaminocarbonylation employs readily available starting materials and tolerates a wide range of functional groups, thus providing a facile and straightforward method for the regio- and enantioselective synthesis of 2-substituted propanamides under ambient conditions. Mechanistic studies revealed that the reaction proceeds through a palladium hydride pathway.
- Yao, Ya-Hong,Yang, Hui-Yi,Chen, Ming,Wu, Fei,Xu, Xing-Xing,Guan, Zheng-Hui
-
supporting information
p. 85 - 91
(2021/01/12)
-
- Preparation method of amide
-
The invention relates to a preparation method of an amide, wherein, under the action of oxygen, the isothiocyanate and the aldehyde can react to form an amide, and the reaction temperature can be effectively increased only when not less than 110 °C. This process is also suitable for the reaction of isocyanates with aldehydes to produce amides. The preparation method is cheap in raw material, wide in substrate application range and free of metal catalysts in the reaction process. The initiator or other activator is green and economical, and can effectively reduce the cost.
- -
-
Paragraph 0055-0079; 0152-0157
(2021/08/25)
-
- Synthesis of Secondary Amides from Thiocarbamates
-
The synthesis of secondary amides from readily accessible and bench-stable substituted S-phenyl thiocarbamates and Grignard reactants is reported. Oxidative workup allows recycling of the thiolate leaving group as diphenyl disulfide. Diphenyl disulfide can be transformed into S-phenyl benzenethiosulfonate, a reactant required for thiocarbamate synthesis. This amide synthesis is suitable for the preparation of challenging amides that are not or hardly accessible via classical approaches.
- Mampuys, Pieter,Ruijter, Eelco,Orru, Romano V. A.,Maes, Bert U. W.
-
supporting information
p. 4235 - 4239
(2018/07/29)
-
- Hypervalent Iodine-Mediated Oxidative Rearrangement of N-H Ketimines: An Umpolung Approach to Amides
-
An umpolung approach to amides via hypervalent iodine-mediated oxidative rearrangement of N-H ketimines under mild reaction conditions is described. This strategy provides target amides with excellent selectivity in good yields. In addition, preliminary m
- Zhao, Zhenguang,Peng, Zhiyuan,Zhao, Yongli,Liu, Hao,Li, Chongnan,Zhao, Junfeng
-
p. 11848 - 11853
(2017/11/28)
-
- Enantioselective inclusion of amide guests into a chiral N,N′-ditrityl amino amide host to compensate the loss of hydrogen bonds broken by installation of trityl groups
-
A new crystalline N,N′-ditrityl amino amide host included several amide guests in the host cavity to form inclusion crystals. Although the installation of trityl groups into (S)-2-aminopropanamide broke its inherent hydrogen bonds of amide groups, inclusion of guest amides compensated the loss of hydrogen bonds. X-ray crystallography showed that these inclusion cavities and host-guest interactions such as hydrogen bonds, van der Waals interaction, and CH?O interactions play important roles for highly enantioselective inclusion. The enantiomeric inclusion was 67% ee (S-form) for N-phenyl 2-methylbutanamide, 82% ee (S-form) for N-phenyl 2-chlorobutanamide, and 83% ee (S-form) for N-phenyl 2-bromobutanamide.
- Megumi, Ken,Yokota, Shohei,Matsumoto, Shoji,Akazome, Motohiro
-
supporting information
p. 707 - 710
(2013/02/23)
-
- Enantioselective hydrogenation of α-substituted acrylic acids catalyzed by iridium complexes with chiral spiro aminophosphine ligands
-
Highly active: Iridium complexes with chiral spiro aminophosphine ligands were synthesized and applied as catalysts for the asymmetric hydrogenation of α-substituted acrylic acids (see scheme). The complexes were highly active catalysts, showing turnover frequencies of up to 6000 h-1, and catalyst loadings could be reduced to 0.01 mol %. Copyright
- Zhu, Shou-Fei,Yu, Yan-Bo,Li, Shen,Wang, Li-Xin,Zhou, Qi-Lin
-
p. 8872 - 8875
(2012/10/08)
-
- Three new glycosides from Viburnum plicatum THUNB. var. tomentosum MIQ
-
Three new glycosides, 7-O-tigloylsecologanol (1), 7-O-tigloylsecologanolic acid (2), and 3'-O-[(2S)-2-methylbutanoyl]henryoside (3), together with seven known ones, were isolated from the leaves of Viburnum plicatum Thunb. var. tomentosum Miq. Their structures were established on the basis of spectral and chemical data.
- Machida, Koichi,Sagawa, Hitomi,Onoguchi, Rie,Kikuchi, Masao
-
experimental part
p. 290 - 297
(2010/05/15)
-
- Highly enantioselective construction of the α-chiral center of amides via iridium-catalyzed hydrogenation of α,β-unsaturated amides
-
The chiral center at the a-position of amides is installed in excellent enantioselectivity via the iridium-catalyzed asymmetric hydrogenation of αβ-unsaturated amides under mild conditions. Even aliphatic amides are suitable substrates. The presence of a
- Lu, Wei-Jing,Hou, Xue-Long
-
supporting information; experimental part
p. 1224 - 1228
(2009/12/06)
-
- Iridium-catalyzed enantioselective hydrogenation of α,β- unsaturated carboxylic acids
-
A highly efficient iridium-catalyzed hydrogenation of α,β-unsaturated carboxylic acids has been developed by using chiral spiro-phosphino-oxazoline ligands, affording α-substituted chiral carboxylic acids in exceptionally high enantioselectivities and reactivities. Copyright
- Li, Shen,Zhu, Shou-Fei,Zhang, Can-Ming,Song, Song,Zhou, Qi-Lin
-
supporting information; experimental part
p. 8584 - 8585
(2009/02/03)
-
- Triphenylphosphine-2,4,4,6-tetrabromo-2,5-cyclohexadienone complex as a reagent for preparation of carboxylic acid bromides
-
Triphenylphosphine-2,4,4,6-tetrabromo-2,5-cyclohexadienone complex was successfully used as a new reagent for the synthesis of carboxylic acid bromides which were isolated as individual substances or were identified by conversion into the corresponding anilides. The reaction is chemoselective, and it can be applied to polyfunctional compounds, e.g., hydroxy acids.
- Matveeva,Podrugina,Sandakova,Zefirov
-
p. 1469 - 1472
(2007/10/03)
-
- Chiral Methacrylic Polymers Containing Permanent Dipole Azobenzene Chromophores. Synthesis and Characterization
-
(S)-4-amino-4'-cyanoazobenzene (MBAC), a new optically active photochromic monomer having a large permanent dipole momenty was prepared in six steps starting from (S)-2-methyl-1-butanol.Homo- and copolymerization of MBAC with butyl methacrylate was carried out in benzene at 70 deg C in the presence of AIBN as a radical initiator.The polymeric materials, having a molar content of MBAC units between 21 and 100percent, were characterized by an almost random distribution of monomeric units and a glass transition temperature ranging from 70 to 110 degC. 2D COSY analysis allowed to attribute all signals of their rather complex 1H NMR spectra and to suggest that intramolecular charge transfer mesomers significantly contribute to the electronic distribution of the azobenzene chromophore.Asymmetric perturbation of the azobenzene chromophore, that could be at least partially attributed to the presence of short-order segments along the polymer chain, was evidenced by circular dichroism.
- Altomare, Angelina,Ciardelli, Francesco,Ghiloni, Maria Stella,Solaro, Roberto
-
p. 143 - 150
(2007/10/03)
-
- Process for producing optically active carboxylic acid
-
A process for the production of an optically active carboxylic acid (I), which comprises subjecting an olefinic carboxylic acid (II) to asymmetric hydrogenation using a complex as a catalyst consisting of an optically active phosphine (III) and a ruthenium compound. Complex of STR1 with a ruthenium compound STR2 According to the process of the present invention, optically active carboxylic acids can be produced with high yield.
- -
-
-