73244-32-3Relevant academic research and scientific papers
Ternary Catalysis Enabled Three-Component Asymmetric Allylic Alkylation as a Concise Track to Chiral α,α-Disubstituted Ketones
Chang, Wenju,Fu, Xiang,Hu, Wenhao,Kang, Zhenghui,Liang, Yong,Tian, Xue,Xu, Xinfang,Zhao, Wenxuan
, p. 20818 - 20827 (2021/12/17)
Multicomponent reactions that involve interception of onium ylides through Aldol, Mannich, and Michael addition with corresponding bench-stable acceptors have demonstrated broad applications in synthetic chemistry. However, because of the high reactivity and transient survival of these in situ generated intermediates, the substitution-type interception process, especially the asymmetric catalytic version, remains hitherto unknown. Herein, a three-component asymmetric allylation of α-diazo carbonyl compounds with alcohols and allyl carbonates is disclosed by employing a ternary cooperative catalysis of achiral Pd-complex, Rh2(OAc)4, and chiral phosphoric acid CPA. This method represents the first example of three-component asymmetric allylic alkylation through an SN1-type trapping process, which involves a convergent assembly of two active intermediates, Pd-allyl species, and enol derived from onium ylides, providing an expeditious access to chiral α,α-disubstituted ketones in good to high yields with high to excellent enantioselectivity. Combined experimental and computational studies have shed light on the mechanism of this novel three-component reaction, including the critical role of Xantphos ligand and the origin of enantioselectivity.
Highly Regio- A nd Enantioselective Hydrogenation of Conjugated α-Substituted Dienoic Acids
Liu, Xian,Liu, Song,Wang, Quanjun,Zhou, Gang,Yao, Lin,Ouyang, Qin,Jiang, Ru,Lan, Yu,Chen, Weiping
supporting information, p. 3149 - 3154 (2020/04/09)
Highly regio- A nd enantioselective hydrogenation of conjugated α-substituted dienoic acids was realized for the first time using Trifer-Rh complex, providing a straightforward method for the synthesis of chiral α-substituted ?,?′-unsaturated acids. DFT calculations revealed N+H-O hydrogen bonding interaction is formed to stabilize the transition state and the coordination of 4,5-double bond to Rh(III) center would facilitate the reductive elimination process. This hydrogenation provided a gram-scale synthesis of the precursor of sacubitril.
Enantioselective α-functionalization of 1,3-dithianes by iridium-catalyzed allylic substitution
Xie, Xingang,Tang, Shouchu,Wang, Xiaolei,Wang, Panpan,Jiang, Qian,Zhao, Ruibo
, p. 12456 - 12467 (2020/11/09)
An iridium-catalyzed asymmetric allylic substitution reaction with 2-alkoxy carbonyl-1,3-dithianes has been achieved with high regio- and enantioselectivities. The transformation provides a new method for the enantioselective α-functionalization of dithianes. The corresponding dithiane-containing products are easily converted into many other derivatives with high yields and enantioselectivities.
Boron-Templated Dimerization of Allylic Alcohols to Form Protected 1,3-Diols via Acid Catalysis
Nazari, S. Hadi,Forson, Kelton G.,Martinez, Erin E.,Hansen, Nicholas J.,Gassaway, Kyle J.,Lyons, Nathan M.,Kenney, Karissa C.,Valdivia-Berroeta, Gabriel A.,Smith, Stacey J.,Michaelis, David J.
, p. 9589 - 9593 (2019/12/02)
We report an unprecedented boron-templated dimerization of allylic alcohols that generates a 1,3-diol product with two stereogenic centers in high yield and diastereoselectivity. This acid-catalyzed reaction is achieved via in situ formation of a boronic ester intermediate that facilitates selective cyclization and formation of a cyclic boronic ester product. High yields are observed with a variety of allylic alcohols, and mechanistic studies confirm the role of boron as a template for the reaction.
Arene Trifunctionalization with Highly Fused Ring Systems through a Domino Aryne Nucleophilic and Diels–Alder Cascade
He, Jia,Jia, Zizi,Tan, Hongcheng,Luo, Xiaohua,Qiu, Dachuan,Shi, Jiarong,Xu, Hai,Li, Yang
, p. 18513 - 18518 (2019/11/19)
A convenient and efficient domino aryne process was developed under transition-metal-free conditions to generate a range of tetra- and pentacyclic ring systems. This transformation was realized via a 1,2-benzdiyne through a nucleophilic and Diels–Alder reaction cascade using styrene as the diene moiety. Three new chemical bonds, namely one C?N and two C?C bonds, and two benzofused rings could be constructed concomitantly, which was made possible by distinct chemoselective control at both the 1,2-aryne and 2,3-aryne stages. Moreover, in-depth studies were carried out on the domino aryne precursors and controlling the diastereoselectivity.
Method for synthesizing unsaturated primary alcohol
-
Paragraph 0029-0033, (2019/08/20)
The invention discloses a method for synthesizing an unsaturated primary alcohol. The method comprises the following steps: adding an unsaturated aldehyde, a transition metal catalyst iridium complexand isopropyl alcohol in a reaction container, heating the reaction mixture in an oil bath, carrying out a reaction for a plurality of hours, then carrying out cooling to room temperature, removing the solvent by rotating evaporation, and then carrying out column separation to obtain the target compound. According to the invention, the unsaturated aldehyde is used as a raw material, isopropyl alcohol is used as a hydrogen source and the solvent, and the unsaturated primary alcohol is generated through hydrogen transfer under participation of the transition metal iridium catalyst. The method has the following remarkable advantages: 1) the reaction temperature is low; 2) cheap, safe and non-toxic isopropanol is used; 3) the catalyst usage amount is low, and reaction atom economy is high; and4) selectivity is good. Therefore, the method meets the requirements of green chemistry and has a wide development prospect.
Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol under Neutral Conditions Catalyzed by a Metal-Ligand Bifunctional Catalyst [Cp?Ir(2,2′-bpyO)(H2O)]
Wang, Rongzhou,Tang, Yawen,Xu, Meng,Meng, Chong,Li, Feng
, p. 2274 - 2281 (2018/02/23)
A Cp?Ir complex bearing a functional bipyridonate ligand [Cp?Ir(2,2′-bpyO)(H2O)] was found to be a highly efficient and general catalyst for transfer hydrogenation of aldehydes and chemoselective transfer hydrogenation of unsaturated aldehydes with isopropanol under neutral conditions. It was noteworthy that many readily reducible or labile functional groups such as nitro, cyano, ester, and halide did not undergo any change under the reaction conditions. Furthermore, this catalytic system exhibited high activity for transfer hydrogenation of ketones with isopropanol. Notably, this research exhibited new potential of metal-ligand bifunctional catalysts for transfer hydrogenation.
Enantioselective Intermolecular Addition of Aliphatic Amines to Acyclic Dienes with a Pd-PHOX Catalyst
Adamson, Nathan J.,Hull, Ethan,Malcolmson, Steven J.
supporting information, p. 7180 - 7183 (2017/06/05)
We report a method for the catalytic, enantioselective intermolecular addition of aliphatic amines to acyclic 1,3-dienes. In most cases, reactions proceed efficiently at or below room temperature in the presence of 5 mol % of a Pd catalyst bearing a PHOX ligand, generating allylic amines in up to 97:3 er. The presence of an electron-deficient phosphine within the ligand not only leads to a more active catalyst but also is critical for achieving high site selectivity in the transformation.
Stereoselective and Site-Specific Allylic Alkylation of Amino Acids and Small Peptides via a Pd/Cu Dual Catalysis
Huo, Xiaohong,He, Rui,Fu, Jingke,Zhang, Jiacheng,Yang, Guoqiang,Zhang, Wanbin
supporting information, p. 9819 - 9822 (2017/08/02)
We report a stereoselective and site-specific allylic alkylation of Schiff base activated amino acids and small peptides via a Pd/Cu dual catalysis. A range of noncoded α,α-dialkyl α-amino acids were easily synthesized in high yields and with excellent enantioselectivities (up to >99% ee). Furthermore, a direct and highly stereoselective synthesis of small peptides with enantiopure α-alkyl or α,α-dialkyl α-amino acids residues incorporated at specific sites was accomplished using this dual catalyst system.
Catalytic asymmetric bromochlorination of aromatic allylic alcohols promoted by multifunctional Schiff base ligands
Huang, Wei-Sheng,Chen, Li,Zheng, Zhan-Jiang,Yang, Ke-Fang,Xu, Zheng,Cui, Yu-Ming,Xu, Li-Wen
supporting information, p. 7927 - 7932 (2016/08/30)
It was found that the tridentate O,N,O-type Schiff base ligand bearing suitable substituents was a highly effective promoter in the catalytic asymmetric bromochlorination reaction, in which the corresponding aromatic bromochloroalcohols with vicinal halogen-bearing stereocenters were formed with perfect regioselectivity, with moderate to excellent enantioselectivities (up to 93% ee), and with good yields and chemoselectivities.
