Stereoselective Access to Alkylidenecyclobutanes through γ-Selective Cross-Coupling Strategies
作者:Michael Eisold、Dorian Didier
DOI:10.1021/acs.orglett.7b01803
日期:2017.8.4
Alkylidenecyclobutanes (ACBs) containing all-carbon quaternary stereocenters were simply and efficiently synthesized by combining boron-homologation and γ-selective cross-coupling strategies. This unique sequence led to excellent regio- and diastereoselectivities in the generation of targeted four-membered rings with up to 99% enantiomeric excess using chiral substrates. In addition to the original
One-Pot Preparation of Stable Organoboronate Reagents for the Functionalization of Unsaturated Four- and Five-Membered Carbo- and Heterocycles
作者:Dorian Didier、Andreas Baumann、Michael Eisold、Arif Music
DOI:10.1055/s-0036-1592004
日期:2018.8
organometallics with boron alkoxides can lead to great stabilization of such species at roomtemperature. A considerable extension of the library of unsaturated strained structures is achieved through these sequences, expanding the potential applicability of such unusual building blocks. Combining a facile preparation of organoboronates with their remarkable stability and functional group tolerance allows
A Convenient Alumination of Functionalized Aromatics by Using the Frustrated Lewis Pair Et<sub>3</sub>Al and TMPMgCl⋅LiCl
作者:Andreas Unsinn、Stefan H. Wunderlich、Anukul Jana、Konstantin Karaghiosoff、Paul Knochel
DOI:10.1002/chem.201301869
日期:2013.10.18
straightforward and efficient alumination of functionalizedarenes by using the frustrated Lewis pair Et3Al and TMPMgCl⋅LiCl (TMP=2,2,6,6‐tetramethylpiperidyl) has been developed. In particular, halogenated electron‐rich aromatics can be smoothly functionalized by using the frustrated Lewis pair Et3Al and TMPMgCl⋅LiCl. Compared with previously described alumination methods, this procedure avoids extensive cooling
Direct Pd-Catalyzed Cross-Coupling of Functionalized Organoaluminum Reagents
作者:Klaus Groll、Tobias D. Blümke、Andreas Unsinn、Diana Haas、Paul Knochel
DOI:10.1002/anie.201205987
日期:2012.10.29
A handsome couple: Through the use of the simple Pd catalyst [Pd(tmpp)2Cl2] (tmpp=tris(2,4,6‐trimethoxyphenyl)phosphine) and THF/DMF as solvent, various aryl‐, heteroaryl‐, benzyl‐ and alkylaluminum reagents can be readily cross‐coupled with aryl or heteroaryl iodides, bromides, and nonaflates, and in special cases even with chlorides and triflates. This cross‐coupling tolerates free NH2 groups, aldehydes
N′‐tetramethylethylenediamine) or InCl3 (0.33 equiv) with [Li(tmp)] (tmp=2,2,6,6‐tetramethylpiperidino; 1.5 or 1.3 equiv, respectively) were compared with the previously described mixture of ZnCl2⋅TMEDA (0.5 equiv) and [Li(tmp)] (1.5 equiv) for their ability to deprotonate anisole, benzothiazole, and pyrimidine. [(tmp)3CdLi] proved to be the best base when used in tetrahydrofuran at room temperature, as demonstrated