B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Hydrodesulfurization Using Hydrosilanes – Metal-Free Reduction of Sulfides
作者:Kodai Saito、Kazumi Kondo、Takahiko Akiyama
DOI:10.1021/acs.orglett.5b01651
日期:2015.7.2
B(C6F5)3-catalyzed hydrodesulfurization of carbon–sulfur bonds was achieved using triethylsilane as the reducing agent. The corresponding products were obtained in good yields under mild reaction conditions. This protocol could be applied to the reduction of sulfides, including benzyl and alkyl sulfides and dithianes, with high chemoselectivities.
使用三乙基硅烷作为还原剂,实现了B(C 6 F 5)3催化的碳硫键加氢脱硫。在温和的反应条件下以高收率获得了相应的产物。该方案可用于具有高化学选择性的硫化物的还原,包括苄基和烷基硫化物以及二噻烷。
Catalytic Asymmetric Addition of Alkyllithium Reagents to Aromatic Aldehydes
Herein, we report the first efficient catalytic system for the asymmetric alkylation of aldehydes with organolithium reagents in the presence of titanium(IV) isopropoxide. A variety of alkyllithium reagents can be added to aromaticaldehydes in good yields with high enantioselectivities in a simple one-pot procedure under mild conditions.
Alkylation of Aldehyde (Arenesulfonyl)hydrazones with Trialkylboranes
作者:George W. Kabalka、John T. Maddox、Ekaterini Bogas、Shane W. Kelley
DOI:10.1021/jo962089q
日期:1997.5.1
(Arenesulfonyl)hydrazone derivatives of aryl aldehydes are readily alkylated by trialkylboranes in the presence of base to generate new organoboranes that may be converted to the corresponding substituted alkanes or alcohols depending upon the reaction conditions chosen. Both tosyl- and trisylhydrazone derivatives can be utilized in the reaction, which tolerates a variety of functional groups, making it a versatile alternative to both the Grignard and Suzuki-coupling reactions.
Asymmetric Synthesis of Biaryl Diols via Dynamic Kinetic Resolution
作者:Jeonghun Cho、Kyungwoo Kim、Jaiwook Park、Mahn‐Joo Kim
DOI:10.1002/bkcs.12337
日期:2021.7
We have developed a protocol incuding dynamic kinetic resolution as the key step for the asymmetricsynthesis of biaryl diol stereoisomers. The two aryl alkanols as the starting materials were cross-coupled by palladium catalysis to give dl- and meso-diol, which were then subject to chemoenzymatic dynamic kinetic resolution (DKR) for the transformation into single stereoisomeric diol diester. Diol
我们开发了一个协议,包括动态动力学分辨率作为联芳二醇立体异构体不对称合成的关键步骤。两个芳基链烷醇作为起始材料是交叉耦合的由钯催化,得到DL -和内消旋-二醇,然后将其经受化学酶促动态动力学拆分( DKR)用于转化成单立体异构体的二醇二酯。二醇二酯最终脱酰化得到相应的联芳二醇立体异构体。化学酶促 DKR 使用基于钌的外消旋化催化剂和 ( R ) 选择性脂蛋白脂肪酶进行。总共 17 ( R , R )-二醇,包括 7 C 2合成了具有优异对映纯度 (>99% ee ) 的 -对称二醇。
Alkylation of aromatic aldehydes with alkylboron chloride derivatives
作者:George W Kabalka、Zhongzhi Wu、Yuhong Ju
DOI:10.1016/s0040-4020(00)01160-1
日期:2001.2
The reaction of aryl aldehydes with alkylboron chlorides has been investigated. Monoalkylboron dichlorides react with aryl aldehydes in hexane under reflux conditions to give a mixture of dichloroarylmethane and benzyl chloride. Under the same reaction conditions, dialkylboron chlorides lead to formation of a mixture of benzyl chloride and the chloroalkylation product. In the presence of a base such