Alkylboronic Esters from Copper-Catalyzed Borylation of Primary and Secondary Alkyl Halides and Pseudohalides
作者:Chu-Ting Yang、Zhen-Qi Zhang、Hazmi Tajuddin、Chen-Cheng Wu、Jun Liang、Jing-Hui Liu、Yao Fu、Maria Czyzewska、Patrick G. Steel、Todd B. Marder、Lei Liu
DOI:10.1002/anie.201106299
日期:2012.1.9
unprecedented copper‐catalyzed cross‐coupling reaction of the title compounds with diboron reagents is described (see scheme; Ts=4‐toluenesulfonyl). This reaction can be used to prepare both primary and secondaryalkylboronic esters having diverse structures and functional groups. The resulting products would be difficult to access by other means.
Expedient Iron-Catalyzed C−H Allylation/Alkylation by Triazole Assistance with Ample Scope
作者:Gianpiero Cera、Tobias Haven、Lutz Ackermann
DOI:10.1002/anie.201509603
日期:2016.1.22
for the iron‐catalyzed C−H allylation of arenes, heteroarenes, and alkenes with ample scope. The versatile catalyst also proved competent for site‐selective methylation, benzylation, and alkylation with challenging primary and secondary halides. Triazole‐assisted C−H activation proceeded chemo‐, site‐, and diastereo‐selectively, and the modular TAM directing group was readily removed in a traceless
S-Substituted-2-thioadenosines represented by the formula (I): ##SPC1## wherein R is as defined hereinafter, useful as a platelet aggregation inhibitor and a coronary vasodilator.
Alkenes, arenes, and heteroarenes possessing an 8-quinolylamide group as the directing group are alkylated with primary and secondary alkyl tosylates, mesylate, and halides in the presence of Fe(acac)3/diphosphine as a catalyst and ArZnBr as a base. The reaction proceeds stereospecifically for alkene substrates and takes place without loss of regiochemical integrity of the starting secondary tosylate
Bench-Stable Stock Solutions of Silicon Grignard Reagents: Application to Iron- and Cobalt-Catalyzed Radical C(sp<sup>3</sup>
)-Si Cross-Coupling Reactions
作者:Weichao Xue、Ryosuke Shishido、Martin Oestreich
DOI:10.1002/anie.201807640
日期:2018.9.10
the preparation of silicon‐based magnesiumreagents is reported. The MgBr2 used in the lithium‐to‐magnesium transmetalation step is generated in situ from 1,2‐dibromoethane and elemental magnesium in hot THF. No precipitation of MgBr2 occurs in the heat, and transmetalation at elevated temperature leads to homogeneous stock solutions of the silicon Grignard reagents that are stable and storable in the