Cross-coupling reactions between 2-methyl-2-propen-1-ol and various boronic acids are used to obtain aromatic-(2-methylallyl) derivatives. However, deboronation or isomerization side reactions may occur for several boronic acids. We describe herein the synthesis of original alkenes with good yields under mild reaction conditions that decrease these side reactions. The scope of this environmentally benign reaction is thereby extended to a wide variety of boronic acids. A mechanistic study was conducted and suggested a plausible catalytic cycle mechanism, pointing to the importance of the Lewis acidity of the boronic acid used.
Photoinduced Dearomatizing Three‐Component Coupling of Arylphosphines, Alkenes, and Water
作者:Yusuke Masuda、Hiromu Tsuda、Masahiro Murakami
DOI:10.1002/anie.202013215
日期:2021.2.15
A unique photoinduced reaction that couples a triarylphosphine, an alkene, and water to produce 2‐(cyclohexa‐2,5‐dienyl)ethylphosphine oxide is reported herein. The alkene inserts into a C(aryl)−P bond of the arylphosphine, the aryl ring is dearomatized into the cyclohexadienyl ring, and the phosphorus is oxidized. The three components are all readily available, and their intermolecular coupling significantly
The fluoride free cross-coupling between aryldimethylsilanes and organic halides proceeded in the presence of monocopper(i) alkoxide of ethylene glycol. The similar reaction of alkenyldimethylsilanes also took place with complete retention of configuration.
Thiourea–I2 as Lewis base–Lewis acid cooperative catalysts are developed for the iodochlorination of alkenes with in situ-generated iodinemonochloride (I–Cl). The Lewis base–Lewis acid cooperative system is sufficient to generate I–Cl from I2 with a chlorinating reagent at low temperature. Based on the solid-state structure of the active species, thiourea–I2 cooperatively captures I–Cl. By taking
硫脲-I 2作为路易斯碱-路易斯酸协同催化剂被开发用于用原位生成的一氯化碘(I-Cl)进行烯烃的碘氯化。刘易斯碱-路易斯酸协同体系足以在低温下用氯化剂从I 2生成I-Cl 。基于活性物质的固态结构,硫脲I 2协同捕获I Cl。通过利用I–Cl生成和在低温下控制I–Cl的优势,硫脲– I 2协同系统抑制了由高反应性游离I–Cl引起的副反应。
Copper(I)-Catalyzed Alkylation of Aryl- and Alkenylsilanes Activated by Intramolecular Coordination of an Alkoxide
Let's coordinate: Copper(I)‐catalyzed cross‐coupling of alkenyl‐ and arylsilanes with primary alkyl iodides as well as allylic and benzylic halides as C(sp3)X electrophilic coupling partners has been realized by intramolecular activation through alkoxide coordination. This alkylation tolerates a range of functional groups including a free hydroxy group. IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene