The facile synthesis of the 5Z,9Z-dienoic acids and their topoisomerase I inhibitory activity
作者:Vladimir A. D'yakonov、Aleksey A. Makarov、Lilya U. Dzhemileva、Elina Kh. Makarova、Elza K. Khusnutdinova、Usein M. Dzhemilev
DOI:10.1039/c3cc44926b
日期:——
original, effective approach to the synthesis of natural and synthetic 5Z,9Z-dienoic acids in high yields (61-67%) and with high selectivity (>98%) was developed. The approach is based on the use of the new intermolecular catalytic cross cyclomagnesiation of terminal aliphatic and oxygenated 1,2-dienes upon treatment with Grignardreagents in the presence of the Cp2TiCl2 catalyst. High activity of (5Z
hydrosilylation of allenes with primary and secondary phenylsilanes. It shows high selectivity towards the production of branched allylsilanes with a wide range of allenes. It is worth mentioning that the catalytic loading of the palladium can be reduced to 500 ppm. This work opens a new front of using bidentate thiophene ligand as a reaction promoter in transition‐metal‐catalyzed organic reaction.
Rhodium-Catalyzed Regio- and Enantioselective Addition of <i>N</i>-Hydroxyphthalimide to Allenes: A Strategy To Synthesize Chiral Allylic Alcohols
作者:Zi Liu、Bernhard Breit
DOI:10.1021/acs.orglett.7b03709
日期:2018.1.5
We achieved the first Rh-catalyzed regio- and enantioselectiveadditions of N-hydroxyphthalimide to allenes. This transformation is accomplished via mild reaction conditions, leveraging on Josiphos SL-J003-2 as a chiral ligand to furnish branched O-allyl compounds in good yields with moderate to excellent enantioselectivities. The substrate scope is broad, and various functional groups are tolerated
Rhodium-Catalyzed Enantioselective Intermolecular Hydroalkoxylation of Allenes and Alkynes with Alcohols: Synthesis of Branched Allylic Ethers
作者:Zi Liu、Bernhard Breit
DOI:10.1002/anie.201603538
日期:2016.7.11
Regio‐ and enantioselective additions of alcohols to either terminal allenes or internal alkynes provides access to allylic ethers by using a RhI/diphenyl phosphate catalytic system. This method provides an atom‐economic way to obtain chiral aliphatic and aryl allylic ethers in moderate to good yield with good to excellent enantioselectivities.
通过末端Rh I /二苯基磷酸酯催化系统,将醇的区域和对映体选择性加成到末端异戊烯或内部炔烃中,即可获得烯丙基醚。该方法提供了一种原子经济的方法,可以以中等至良好的收率以及良好至优异的对映选择性获得手性脂肪族和芳基烯丙基醚。
Rhodium‐Catalyzed Asymmetric Allylation of Malononitriles as Masked Acyl Cyanide with Allenes: Efficient Access to β,γ‐Unsaturated Carbonyls
作者:Christian P. Grugel、Bernhard Breit
DOI:10.1002/chem.201804150
日期:2018.10.12
A rhodium‐catalyzed regio‐ and enantioselective intermolecular allylation of malononitriles as masked acyl cyanides (MAC) with terminal and symmetrical internal allenes is reported. A RhI/Josiphos catalytic system combined with subsequent oxidative degradation of the primary adducts enables a straightforward access to α‐branched, β,γ‐unsaturated carbonyl compounds. The present protocol exhibits perfect
报道了铑催化的丙二腈的区域和对映选择性分子间烯丙基化反应,即带有末端和对称内部烯基的掩蔽酰基氰化物(MAC)。Rh I / Josiphos催化体系与随后的一级加合物的氧化降解相结合,可以直接获得α支化,β,γ-不饱和羰基化合物。本方案在烯丙基化步骤中展现出完美的原子经济性,并且具有良好的官能团相容性。此外,使用α-取代的丙二腈可以构建全碳四元中心。