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
Facile Direct Coupling Reactions of
<scp>MOM</scp>
‐protected Benzylic Alcohols Using Aluminum Chloride
作者:Tien Tan Bui、Hee‐Kwon Kim
DOI:10.1002/bkcs.12358
日期:2021.9
used protecting groups for alcohols. This study describes novel direct functionalization of the MOM-protected benzylic alcohols. Preparation of allylic compounds from benzyl MOM ethers was successfully achieved by utilization of allyltrimethylsilane and AlCl3. In addition, direct azidation of benzyl MOM ethers using TMSN3 was successful carried out under AlCl3-mediated reaction conditions. These results
Substrate-Controlled Highly Diastereoselective Synthesis of Primary and Secondary Diorganozinc Reagents by a Hydroboration/Boron–Zinc Exchange Sequence
作者:Eike Hupe、M. Isabel Calaza、Paul Knochel
DOI:10.1002/chem.200204662
日期:2003.6.16
The scope of substrate-controlleddiastereoselectivehydroborations can be considerably enhanced by a boron-zincexchange reaction, providing organozinc derivatives that react with a broad range of electrophiles. Even normally unreactive boronic esters, obtained by Rh-catalyzed hydroboration with catecholborane, react readily with iPr2Zn providing the corresponding zinc reagents in high diastereoselectivity
Silylated cyclopentadienes as competent silicon Lewis acid catalysts
作者:M. Alex Radtke、Tristan H. Lambert
DOI:10.1039/c8sc02279h
日期:——
The synthesis and characterization of silicon Lewis acid complexes that incorporate highly electron-deficient cyclopentadienes is reported. Several pentacarboxycyclopentadienyl and monocarboxytetracyanocyclopentadienyl complexes were prepared. A comparison of their reactivities for catalysis of the allylation of an electron-deficient benzaldehyde was established. The use of a monocarboxytetracyano