Kinetic Resolution of Aziridines Enabled by N‐Heterocyclic Carbene/Copper Cooperative Catalysis: Carbene Dose‐Controlled Chemo‐Switchability
作者:Zi‐Jing Zhang、Yu‐Hua Wen、Jin Song、Liu‐Zhu Gong
DOI:10.1002/anie.202013679
日期:2021.2.8
dynamic kinetic asymmetric transformation (DyKAT) are alternative and complementary avenues to access chiral stereoisomers of both starting materials and reaction products. The development of highly efficient chiral catalytic systems for kinetically controlled processes has therefore been one of the linchpins in asymmetric synthesis. N‐heterocyclic carbene (NHC)/copper cooperative catalysis has enabled
Catalyst-controlled divergent intermolecularcycloadditions of vinylaziridines with alkynes have been developed. By using [Rh(NBD)2]BF4 as the catalyst, a [3 + 2] cycloaddition reaction was achieved with broad substrate scope and high stereoselectivity under mild reaction conditions. Moreover, the chirality of vinylaziridines can be completely transferred to the [3 + 2] cycloadducts. When the catalyst
Diborylalkyllithium Salts Trigger Regioselective Ring Opening of Vinyl Aziridines
作者:Oriol Salvado、Riccardo Gava、Elena Fernández
DOI:10.1021/acs.orglett.9b03672
日期:2019.11.15
nucleophilic attack on vinyl aziridines with controlled regioselectivity. Preferred SN2 diborylalkylation ringopening reaction on the less sterically hindered position is observed with 1-tosyl-2-vinylaziridine, whereas exclusive SN2′ nucleophilic attack occurs on 2-methyl-1-tosyl-2-vinylaziridine. Cyclic vinyl aziridines interact through a third venue, via SN2 diborylalkylation ringopening reaction on the allylic
经LiTMP处理的gem -Diborylalkanes生成α-diborylalkane锂碱,该碱对区域的乙烯基氮丙啶进行亲核攻击,并具有可控的区域选择性。优选的小号Ñ就少的空间位阻的位置2 diborylalkylation开环反应与1-甲苯磺酰基-2- vinylaziridine观察到的,而排斥小号Ñ上2-甲基-1-对甲苯磺酰-2- vinylaziridine发生2'的亲核攻击。环状乙烯基氮丙啶经由烯丙基位置上的S N 2二硼烷基烷基化开环反应通过第三位点相互作用。在完全立体化学控制下形成均烯丙基二硼酸酯。
Chemo-, Regio-, and Stereoselective Silver-Catalyzed Aziridination of Dienes: Scope, Mechanistic Studies, and Ring-Opening Reactions
作者:Josep Llaveria、Álvaro Beltrán、W. M. C. Sameera、Abel Locati、M. Mar Díaz-Requejo、M. Isabel Matheu、Sergio Castillón、Feliu Maseras、Pedro J. Pérez
DOI:10.1021/ja412547r
日期:2014.4.9
of 2,4-diene-1-ols in a chemo-, regio-, and stereoselective manner to give vinylaziridines in high yields by means of the metal-mediated transfer of NTs (Ts = p-toluensulfonyl) units from PhI═NTs. The preferential aziridination occurs at the double bond neighboring to the hydroxyl end in ca. 9:1 ratios that assessed a very high degree of regioselectivity. The reaction with the silver-based catalysts
Stereoselective Lewis Acid Mediated (3+2) Cycloadditions of<i>N</i>-H- and<i>N</i>-Sulfonylaziridines with Heterocumulenes
作者:Robert A. Craig、Nicholas R. O'Connor、Alexander F. G. Goldberg、Brian M. Stoltz
DOI:10.1002/chem.201303699
日期:2014.4.14
Alkyl and arylisothiocyanates and carbodiimides are effective substrates in (3+2) cycloadditions with N‐sulfonyl‐2‐substituted aziridines and 2‐phenylaziridine for the synthesis of iminothiazolidines and iminoimidazolidines. Additionally, the stereoselective (3+2) cycloaddition of N‐H‐ and N‐sulfonylaziridines with isothiocyanates can be accomplished, allowing for the synthesis of highly enantioenriched