Stille and Suzuki Cross-Coupling Reactions as Versatile Tools for Modifications at C-17 of Steroidal Skeletons - A Comprehensive Study
作者:Vanessa Koch、Martin Nieger、Stefan Bräse
DOI:10.1002/adsc.201601289
日期:2017.3.6
cross‐coupling study of steroidal vinyl (pseudo)halides with different boronic acids and tributyltin organyls. Furthermore, we have investigated the “inverse” case of those cross‐coupling reactions, i.e., the reaction of a steroidal vinylpinacolatoborane or a tributyltin steroid with various bromides. The development of both methods allows the introduction of different residues at C‐17 of steroid skeletons
Synthesis of a Pondaplin Dimer and Trimer. Aromatic Interactions in Novel Macrocycles
作者:Michael S. Leonard、Patrick J. Carroll、Madeleine M. Joullié
DOI:10.1021/jo0356006
日期:2004.4.1
oxabicyclo[2.2.2]octenone moiety as a masked arene for the synthesis of pondaplin are disclosed. During the course of a study of the Heck reaction as a tool for macrocyclization to provide strained paracyclophanes, novel macrocycles displaying intra- and intermolecular aromatic interactions have been synthesized. The geometry of these interactions is compared to recent computational literature data.
Unusual stereoselectivity in Diels-Alder cycloadditions of 5-bromopyrone
作者:Kamyar Afarinkia、Natasha T. Daly、Silvia Gomez-Farnos、Shravan Joshi
DOI:10.1016/s0040-4039(97)00352-3
日期:1997.3
5-Bromopyrone undergoes cycloaddition to poorly activated or unactivated alkenes to afford high yields of cycloadducts. The regiochemistry of the cycloaddition is excellent. The stereoselectivity of cycloaddition depends on both electronic and steric factors in the dienophile but can be controlled to give predominantly endo or predominantly exo cycloadducts.
D-A cycloadditions of 3,5-dibromo-2-pyrone were investigated with a series of electronically and sterically distinct dienophiles. Our results showed that it is a highly potent ambident diene, being more reactive and stereoselective than monobromo-2-pyrones, and thus capable of generating a variety of bicycloadducts in much higher chemical yields and endo/exo ratios than monobromo-2-pyrones. Another
Stereoselective construction of a key hydroindole precursor of epidithiodiketopiperazine (ETP) natural products
作者:Minghao Feng、Xuefeng Jiang
DOI:10.1039/c4cc04148h
日期:——
The functionalized hexahydroindole scaffold of ETPs was constructed by an asymmetric strategy involving a diastereoselective inverse electron-demand Diels–Alder (IEDDA) reaction.