work, a mild and transition‐metal‐free approach for the nucleophilic aromatic substitution (SNAr) of unactivated fluoroarenes with primary aliphatic amines to form aromatic amines is reported. This reaction is facilitated by the formation of cationic fluoroarene radical intermediates in the presence of an acridinium‐based organic photocatalyst under blue‐light irradiation. Various electron‐rich and
Chemo- and Enantioselective Brønsted Acid-Catalyzed Reduction of α-Imino Esters with Catecholborane
作者:Dieter Enders、Andreas Rembiak、Bianca Anne Stöckel
DOI:10.1002/adsc.201300352
日期:2013.7.8
The chemo‐ and enantioselectivereduction of α‐imino esters with catecholborane has been developed employing 10 mol% of an enantiopure BINOL‐based phosphoric acid as organocatalyst. Various differently substituted aromatic α‐amino acid derivatives can be achieved in almost quantitative yields and very good to excellent enantioselectivities of up to 96% ee under mild reaction conditions.
Chiral bipyridine-annulated bicyclo[3.3.1]nonane N-oxide organocatalysts for stereoselective allylation and hydrosilylation reactions
作者:Simona Žeimytė、Sigitas Stončius
DOI:10.1016/j.tet.2020.131831
日期:2021.1
The synthesis of chiral C2-symmetric bis(bipyridine N,N′-dioxide) and bis(bipyridine N-monooxide) derivatives featuring bipyridine-annulated bicyclo[3.3.1]nonane framework is reported. The new Lewis basic bipyridine N,N′-dioxides exhibited good catalytic activity in the asymmetric allylation of aldehydes with allyltrichlorosilane, furnishing corresponding homoallylic alcohols in up to 75% ee. Reduction
Enantioselective one-pot three-component synthesis of propargylamines catalyzed by copper(I)–pyridine bis-(oxazoline) complexes
作者:Alakesh Bisai、Vinod K. Singh
DOI:10.1016/j.tet.2011.05.114
日期:2012.4
s-Bu-pybox-diPh 2c. The process is simple and allows the synthesis of various propargylamines in good to excellent enantioselectivities (up to 99% ee) and in higher yields. The nature of the substituents attached to imines plays a vital role on the enantioselectivities obtained. The presence of gem-diphenyl group at C-5 position and secondary alkyl substituents at the C-4 chiral center of the oxazoline
i -Pr-pybox-diPh 2b或s -Bu-pybox-diPh 2c的铜(I)络合物已有效催化了在末端炔烃存在下一锅三醛的醛和胺偶联反应。该方法是简单的并且允许以良好至优异的对映选择性(高达99%ee)和更高的产率合成各种炔丙基胺。与亚胺连接的取代基的性质对获得的对映选择性具有至关重要的作用。宝石的存在发现手性配体的恶唑啉环的C-5位上的-二苯基基团和C-4手性中心上的仲烷基取代基对于更高的对映选择性是至关重要的。还提出了一种涉及π–π堆积的过渡态模型以用于立体化学结果。
Enantioselective Organocatalytic Transfer Hydrogenation of α‐Imino Esters by Utilization of Benzothiazoline as Highly Efficient Reducing Agent
作者:Chen Zhu、Takahiko Akiyama
DOI:10.1002/adsc.201000328
日期:2010.10.9
Benzothiazoline was employed as an efficient and versatile reducing agent for the chiral phosphoric acid-catalyzed transfer hydrogenation of α-iminoesters. The corresponding α-amino esters were furnished with excellent enantioselectivities. Novel and readily removable benzothiazolines bearing a hydroxy group were also investigated.