Chemo- and regioselective reductive transposition of allylic alcohol derivatives <i>via</i> iridium or rhodium catalysis
作者:Rylan J. Lundgren、Bryce N. Thomas
DOI:10.1039/c5cc07993d
日期:——
The selective, catalytic deoxygenation of alcohols remains a persistent challenge in organic synthesis. Pd-catalyzed formate reduction and diazene-mediated reductivetransposition are both valuable strategies for the selective deoxygenation of allylic...
Iridium‐Catalyzed Propenylation Reactions for the Synthesis of 4‐Pyridone Derivatives
作者:Xue‐dan Bai、Jie Wang、Ying He
DOI:10.1002/adsc.201801177
日期:2019.2
propenylation reaction of allylic carbonates with 4‐hydroxypyridine derivatives. The process efficiently provides 4‐pyridone derivatives with high stereoselectivities under mild conditions. The products could constitute valuable building blocks for the synthesis of natural products and other bioactive molecules. Preliminary mechanistic studies indicated that a tandemallylic substitution/isomerization
Stereodivergent Synthesis of α,α-Disubstituted α-Amino Acids via Synergistic Cu/Ir Catalysis
作者:Liang Wei、Qiao Zhu、Shi-Ming Xu、Xin Chang、Chun-Jiang Wang
DOI:10.1021/jacs.7b12174
日期:2018.1.31
Cu/Ir dualcatalysis has been developed for the stereodivergent α-allylation of aldimine esters. The method enables the preparation of a series of nonproteinogenic α-amino acids (α-AAs) bearing two contiguous stereogenic centers in high yield with excellent stereoselectivity. All four product stereoisomers could be obtained from the same set of starting materials via pairwise combination of two chiral
A highly regioselective palladium-catalyzed allylic alkylation of dienyl esters with nitromethane has been developed, providing selective access to the C-5 attacked products. The structures of the ligands as well as the steric effect of the substrates are important factors in determining the regiochemical outcome of the reaction.
An Ir/Zn Dual Catalysis for Enantio- and Diastereodivergent α-Allylation of α-Hydroxyketones
作者:Xiaohong Huo、Rui He、Xiao Zhang、Wanbin Zhang
DOI:10.1021/jacs.6b06156
日期:2016.9.7
An Ir/Zn dual catalysis has been developed for the enantio- and diastereodivergent alpha-allylation of unprotected alpha-hydroxyketones under mild conditions, in the absence of any additional base. The cooperative action of a chiral iridium complex derived from phosphoramidites and a chiral Zn-ProPhenol complex is most likely responsible for its high reactivity, excellent enantioselectivity (up to >99% ee), and good diastereoselectivity (up to >20:1 dr). All four product stereoisomers could be prepared from the same set of starting materials and under identical conditions by simple selection of appropriate catalyst combinations.