Catalytic chemoselective [3+3] cycloadditions of azomethine ylides with quinone monoimides leading to the construction of a dihydrobenzoxazine scaffold
Catalytic chemoselective [3+3] cycloadditions of azomethine ylides with quinone monoimides leading to the construction of a dihydrobenzoxazine scaffold
A chiral thiourea catalyst possessing an amine function catalyzes an asymmetric [3+2] cycloaddition of azomethineylides to nitroolefins to provide highly functionalized pyrrolidines with high diastereo- and enantioselectivities (up to 98:1:1 dr, 92% ee). The reaction proceeds in a stepwise manner consisting of Michael addition and subsequent intramolecular aza-Henry reaction. Both reactions are promoted
Iridium-Catalyzed Diastereo- and Enantioselective [4 + 3] Cycloaddition of 4-Indolyl Allylic Alcohols with Azomethine Ylides
作者:Wu-Lin Yang、Tao Ni、Wei-Ping Deng
DOI:10.1021/acs.orglett.0c04132
日期:2021.1.15
[4 + 3] cycloaddition of racemic 4-indolyl allylic alcohols with azomethineylides is reported. The ability of acid promoter zinc triflate to perform multiple roles is the key factor for the success of this strategy. This method provides scalable and efficient access to biologically important azepino[3,4,5-cd] indoles in good yields with generally excellent diastereo- and enantioselectivities (up to
据报道空前的铱催化的外消旋4-吲哚基烯丙基醇与偶氮甲碱的不对称[4 + 3]环加成反应。酸促进剂三氟甲磺酸锌发挥多种作用的能力是该策略成功的关键因素。该方法可提供具有高收率的生物学上重要的azepino [3,4,5- cd ]吲哚的可扩展且有效的途径,通常具有出色的非对映和对映选择性(高达> 20:1 dr和> 99%ee)。温和的反应条件,易于接近的底物和手性催化剂以及广泛的底物范围突出了该方法的实用性。
Iridium-Catalyzed Asymmetric Cascade Allylation/Pictet–Spengler Cyclization Reaction for the Enantioselective Synthesis of 1,3,4-Trisubstituted Tetrahydroisoquinolines
作者:Wu-Lin Yang、Tian-Tian Liu、Tao Ni、Bin Zhu、Xiaoyan Luo、Wei-Ping Deng
DOI:10.1021/acs.orglett.1c00709
日期:2021.4.2
An iridium-catalyzed trifluoroacetic acid-promoted asymmetric cascade allylation/Pictet–Spengler cyclization reaction of azomethine ylides with aromatic allylic alcohols is reported. This protocol provides a facile and scalable method for the construction of 1,3,4-trisubstituted tetrahydroisoquinolines containing two stereogenic centers in good yields (up to 96%) with generally excellent diastereo-
Efficient Methods for the Synthesis of Benzopyrano[3,4-<i>c</i>]pyrrolidines by Catalyzed 1,3-Dipolar Cycloaddition of Azomethine Ylides with 3-Substituted Coumarins
Abstract With triethylamine as a catalyst, the 1,3-dipolarcycloaddition of azomethine ylides with 3-substituted coumarins proceeded smoothly under mild conditions to afford the desired products benzopyrano[3,4-c]pyrrolidines in good to excellent yields.