Preparation of Functionalized Alkylmagnesium Derivatives Using an I/Mg-Exchange

Abstract

Functionalized alkylmagnesium reagents bearing an acetal, a ketal, an ester, or a pyridine ring were prepared by an I/Mg-exchange using iPr2Mg.LiCl or ClMg(CH2)5MgCl.2LiCl starting from functionalized primary alkyl iodides.

Bimetallic Combinations for Dehalogenative Metalation Involving Organic Compounds

“…In 2008, Knochel and co-workers reported the formation of sp 3 -hybridized Grignard reagents by iodine/magnesium exchange between i -Pr 2 Mg·LiCl or ClMg(CH 2 ) 5 MgCl·2LiCl and functionalized primary alkyl iodides bearing oxygen or nitrogen atoms in the γ-position to the carbon–iodine bond. The resulting species were trapped with electrophiles (Table ) …”

“…The resulting species were trapped with electrophiles (Table 69). 92 In 2009, the same group described the stereoselective synthesis of functionalized cyclopropylmagnesium compounds by reaction of cyclopropyl bromides with i-PrMgCl•LiCl in THF−dioxane or s-Bu 2 Mg•LiCl. Bromine/magnesium exchange with complete retention of configuration was observed.…”

Herstellung von primären und sekundären Dialkylmagnesiumverbindungen durch eine radikalische I/Mg‐Austauschreaktion mit sBu2Mg in Toluol

“…i PrMgCl ⋅ LiCl [10] oder s Bu 2 Mg ⋅ 2 LiOR [11] sind hocheffiziente Austauschreagenzien, die für die Herstellung von ungesättigten Aryl‐, Heteroaryl‐ und Alkenylmagnesiumreagenzien weit verbreitet sind. Die Herstellung von Alkylmagnesiumderivaten mit Hilfe eines I/Mg‐Austauschs ist jedoch in der Literatur kaum beschrieben und leidet unter einem sehr engen Substratbereich, der auf primäre Alkyliodide mit einer entfernten Sauerstoff‐Koordinationsgruppe am Alkyliodid beschränkt ist (Schema 1a) [12] . Ein allgemeineres Protokoll für die Herstellung von Alkylmagnesiumreagenzien wäre daher sehr wünschenswert.…”

Preparation of Functionalized Lithium, Magnesium, Aluminum, Zinc, Manganese­, and Indium Organometallics from Functionalized Organic Halides

“…The reaction of pyridine derivative 450 with this complex led, after 1.5 hours between 0 and 25°C, to the Grignard reagent 451 which itself reacted with carbon dioxide to provide the final carboxylic acid 452 in 75% yield. 143 Similarly, acetal 453 underwent a smooth exchange reaction with the bis-Grignard reagent 454. Subsequent quenching of the corresponding alkylmagnesium species 455 with benzaldehyde furnished the expected alcohol 456 in 72% yield (Scheme 78).…”