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。
Rhodium-catalyzed regioselective addition of thioacids to terminal allenes: enantioselective access to branched allylic thioesters
作者:A. Ziyaei Halimehjani、B. Breit
DOI:10.1039/d1cc06470c
日期:——
Rhodium-catalyzed regio- and enantioselective hydrothiolation of terminal allenes with thioacids is reported for the atom-economic synthesis of chiral branched allylic thioesters. By using a rhodium(I) catalyst system, diversities of terminal allenes and thioacids afforded the corresponding branched thioesters in excellent regioselectivity, high yield, and good enantioselectivity. This method was also explored
据报道,在手性支链烯丙基硫酯的原子经济合成中,铑催化的末端丙二烯与硫代酸的区域选择性和对映选择性氢硫醇化反应。通过使用铑( I )催化剂体系,末端丙二烯和硫代酸的多样性提供了相应的支链硫酯,具有优异的区域选择性、高收率和良好的对映选择性。该方法还探索了 Fmoc 保护的氨基硫代酸,用于非对映选择性合成相应的硫酯。
Chemo-, regio-, and enantioselective synthesis of allylic nitrones <i>via</i> rhodium-catalyzed addition of oximes to allenes
作者:Yu-Hsuan Wang、Bernhard Breit
DOI:10.1039/c9cc03391b
日期:——
first chemo-, regio-, and enantioselective rhodium-catalyzed addition of oximes to allenes is reported. Using a Rh(I)/Josiphos catalyst system under mild conditions, the construction of allylic C–N bonds instead of C–O bonds was achieved. This method permits the atom-economic synthesis of branched allylic nitrones in good to quantitative yields with excellent enantioselectivities.
Rhodium-Catalyzed Enantioselective N-Allylation of Sulfoximines
作者:Yang-yang Li、Bing Gao
DOI:10.1021/acs.orglett.3c00414
日期:2023.4.28
The N-functionalization of free sulfoximines is an important approach to modifying their chemical and biological properties for downstream applications. Here, we report a rhodium-catalyzed N-allylation of free sulfoximines (═NH) with allenes under mild conditions. The redox-neutral and base-free process enables chemo- and enantioselective γ-hydroamination of allenes and gem-difluoroallenes. Synthetic