This report describes the enantioselective reduction of structurally diverse α,β-unsaturated ketones and aryl ketones by perakine reductase (PR) from Rauvolfia. This enzymatic reduction produces α-chiral allylic and aryl alcohols with excellent enantioselectivity and most of the products in satisfactory yields. Furthermore, the work demonstrates 1 mmol scale reactions for product delivery without any
Enantioselective Aminocatalytic [2 + 2] Cycloaddition through Visible Light Excitation
作者:Thomas Rigotti、Rubén Mas-Ballesté、José Alemán
DOI:10.1021/acscatal.0c01413
日期:2020.5.1
to obtain enantioenriched cyclobutanes through [2 + 2] photocycloaddition under visiblelight irradiation is presented. This metal-free process does not require the use of any external photocatalyst, as it is catalyzed by a simple diamine which, upon condensation with an enone substrate, forms an iminium ion intermediate that absorbs in the visiblelight region. The direct excitation of such an intermediate
Synthesis of New Phosphonoamide and Phosphonocaprolactam Derivatives via the Diethyl Chlorophosphate-Promoted Beckmann Rearrangement of γ-Phosphonyloximes
作者:Aymen Wahbi、Soufiane Touil
DOI:10.1002/hc.21273
日期:2015.11
Herein, we report an efficient and straightforward synthesis of new phosphonoamide and phosphonocaprolactam derivatives, via the Beckmann rearrangement of γ-phosphonyloximes. The reaction proceeded smoothly in the presence of diethyl chlorophosphate as a promoter, to afford the title compounds in satisfactory yields. A mechanistic rationalization for this reaction is provided allowing for the prediction
Probing the Visible Light‐Driven Geometrical Isomerization of 4‐Arylbut‐3‐ene‐2‐amines
作者:Timothy Schoch、Hannah Wyneken、Megan Despain、Jimmie D. Weaver
DOI:10.1002/cctc.202301002
日期:2023.11.22
Instantiated with a set of styrylamines, parameters affecting photosensitized alkene geometrical isomerization were investigated. Raised temperature was found to reduce inherent Z-enrichment, bulky arenes reinforced Z-enrichment, and certain heterocycles favored accumulation of E isomer. Actinometric assessment was made on the influence of arene bulk, solvent, and presence of oxygen on the reaction
用一组苯乙烯胺实例化,研究了影响光敏烯烃几何异构化的参数。研究发现升高的温度会减少固有的 Z 富集,大体积芳烃会增强 Z 富集,并且某些杂环有利于 E 异构体的积累。对芳烃本体、溶剂和氧的存在对反应速率的影响进行光化评估。
Catalytic enantioselective synthesis of 2-pyrazolines via one-pot condensation/6π-electrocyclization: 3,5-bis(pentafluorosulfanyl)-phenylthioureas as powerful hydrogen bond donors
作者:Moises A. Romero Reyes、Subhradeep Dutta、Minami Odagi、Chang Min、Daniel Seidel
DOI:10.1039/d4sc04760e
日期:——
A new conjugate-base-stabilized carboxylic acid (CBSCA) containing a 3,5-bis(pentafluorosulfanyl)phenylthiourea functionality catalyses challenging one-pot condensations/6π-electrocyclizations of hydrazines and α,β-unsaturated ketones under mild conditions. Structurally diverse N-aryl 2-pyrazolines are obtained in good yields and enantioselectivities. The superior performance of 3,5-bis(SF5)phenylthioureas