Über Mannichbasen, 21. Mitt.1) Austauschreaktionen von Phenolmannichbasen
作者:Hans Möhrle、Christoph Miller
DOI:10.1002/ardp.19833160309
日期:——
Verschiedene p‐Phenolmannichbasen und in geringerem Umfang auch o‐Derivate erleiden beim Erhitzen in wäßrig‐alkoholischem Milieu unter Zusatz von Na2EDTA oder Essigsäure Amin‐Eliminierung mit anschließender Addition der Lösungsmittel an das Chinon‐Methid zu entsprechenden Alkoholen und Ethern.
Enantioselective 1,6-Addition of β-Ketoester Enolates to <i>In Situ</i> Generated <i>para</i>-Quinone Methides Enabled by Cooperative Palladium and Brønsted Acid Catalysis
作者:Cornelius V. Gärtner、Christoph Schneider
DOI:10.1021/acs.orglett.2c04127
日期:2023.1.20
We report herein an asymmetric cooperative process for the enantioselective 1,6-addition of β-ketoesters to in situ generated para-quinone methides with chiral Pd–aqua complexes as mixed Brønsted acid–base catalysts. Excellent yields, outstanding enantiocontrol, and good diastereoselectivity across a broad substrate range are highlights of this transformation. The utility of this reaction is further
Accessing <i>para</i>-Alkylphenols via Iridium-Catalyzed Site-Specific Deoxygenation of Alcohols
作者:Jing Wang、Tingting Wang、Hongguang Du、Ning Chen、Jiaxi Xu、Zhanhui Yang
DOI:10.1021/acs.joc.3c01294
日期:2023.9.1
An iridium-catalyzed and phenol-directed deoxygenation of benzylic alcohols comes as an alternative access to 4-alkylphenols, featuring low catalyst loading (S/C up to 20,000, TOF up to 12,400 h–1), high functionality compatibility, and excellent site-selectivity. The applications in late-stage modification of steroids and gram-scale total synthesis of a Gastrodia elata extract are highlighted. Mechanistically
铱催化和苯酚引导的苄醇脱氧是制备 4-烷基苯酚的替代方案,具有催化剂负载量低(S / C高达 20,000,TOF 高达 12,400 h –1)、高功能兼容性和优异的现场性等特点-选择性。重点介绍了天麻提取物在类固醇后期修饰和克级全合成中的应用。从机理上讲,醌甲基化物的中间作用控制了位点选择性,氢化铱的形成作为限速步骤。
Koutek,B. et al., Collection of Czechoslovak Chemical Communications, 1976, vol. 41, p. 2250 - 2255
作者:Koutek,B. et al.
DOI:——
日期:——
MOEHRLE, H.;MILLER, C., ARCH. PHARM., 1983, 316, N 3, 229-236