Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
作者:Dianhu Zhu、Leiyang Lv、Chen-Chen Li、Sosthene Ung、Jian Gao、Chao-Jun Li
DOI:10.1002/anie.201809112
日期:2018.12.10
carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo‐ and regioselective direct palladium‐catalyzed C‐allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallicreagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not
The cross-couplingreaction of allyl boronester with 1°/2°/3°-halogenated alkanes in the presence of copper has been developed for the first time, which provides a mild and efficient method for the construction of saturated C(sp3)–C(sp3) bonds. This protocol shows excellent compatibility with the nonactivated primary, secondary, and even tertiary halogenated alkanes under mild conditions.
Rhodium(III)-Catalyzed Three-Component 1,2-Diamination of Unactivated Terminal Alkenes
作者:Sumin Lee、Young Jin Jang、Erik J. T. Phipps、Honghui Lei、Tomislav Rovis
DOI:10.1055/s-0039-1690756
日期:2020.4
report a three-component diamination of simple unactivated alkenes using an electrophilic nitrene source and amine nucleophiles. The reaction provides rapid access to 1,2-vicinal diamines from terminal alkenes through a one-pot protocol. The transformation proceeds smoothly with excellent tolerance for a broad array of primary and secondary amines, affording the desired products in good yield and regioselectivity
High-Yielding and Rapid Carbon-Carbon Bond Formation from Alcohols: Allylation by Means of TiCl4
作者:Alfred Hassner、Chennakesava Bandi
DOI:10.1055/s-0033-1338746
日期:——
TiCl4 efficientlypromotes high yield (80–99%) replacement of OH in tertiary, benzylic, and allylic alcohols, and even nonactivated secondary alcohols, by an allyl group. The reaction usually proceeds within minutes at room temperature.
A Rh(III)-Catalyzed Formal [4+1] Approach to Pyrrolidines from Unactivated Terminal Alkenes and Nitrene Sources
作者:Sumin Lee、Honghui Lei、Tomislav Rovis
DOI:10.1021/jacs.9b07012
日期:2019.8.14
formal [4+1] approach to pyrrolidines from readily available unactivated terminalalkenes as 4-carbon partners. The reaction provides a rapid construction of various pyrrolidine containing structures, especially for the diastereoselective synthesis of spiro-pyrrolidines. Mechanistic investigation suggests a Rh(III)-catalyzed intermolecular aziridination of the alkene and subsequent acid-promoted ring expansion