Direct Reduction of Allylic Alcohols Using Isopropanol as Reductant
作者:Masahiro Sai
DOI:10.1002/adsc.201800731
日期:2018.9.17
lithium cation‐catalyzed direct reduction of allylicalcohols to alkenes using isopropanol as a hydride donor was developed. The hydride transfer of the in situ‐generated lithium isopropoxide to an allylic cation is the key process in this transformation. The reaction generates only water and acetone as byproducts, which highlights the synthetic utility of this method.
作者:Yulei Wang、Zhipeng Lin、João C. A. Oliveira、Lutz Ackermann
DOI:10.1021/acs.joc.1c00682
日期:2021.11.19
The oxidative intermolecular nitrogenation of C(sp3)–H bonds represents one of the most straightforward strategies to construct nitrogen-containing molecules. However, a sacrificial chemical oxidant is generally required. Herein, we describe electrochemical oxidative intermolecular allylic C(sp3)–Haminations in an undivided cell by electric current. The cross-dehydrogenative amination proceeded efficiently
C(sp 3 )-H 键的氧化分子间氮化代表了构建含氮分子的最直接的策略之一。然而,通常需要牺牲化学氧化剂。在此,我们通过电流描述了未分割电池中的电化学氧化分子间烯丙基 C(sp 3 )-H 胺化。在无金属和无化学氧化剂的反应条件下,交叉脱氢胺化反应在大范围内有效进行,得到分子 H 2作为唯一的副产物。
Implanting Nitrogen into Hydrocarbon Molecules through CH and CC Bond Cleavages: A Direct Approach to Tetrazoles
作者:Feng Chen、Chong Qin、Yuxin Cui、Ning Jiao
DOI:10.1002/anie.201105505
日期:2011.11.25
From simple beginnings: A novel Cu‐promoted direct incorporation of nitrogen into simple hydrocarbon molecules under mild and neutral reaction conditions is described. 1,5‐Disubstituted tetrazoles are efficiently constructed by two CH and one CCbondcleavages (see scheme; TMS=trimethylsilyl). This protocol provides a new and unique strategy to functionalize simple and readily available hydrocarbon
Something functional: The title reaction proceeds in the presence of azide and water to deliver amides in high yields, and it can be used in a ring‐expansion strategy to generate lactams. A mechanism is proposed based on experimental results. This reaction offers a new approach to functionalizing simple and readily available hydrocarbons. DDQ=2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone.
A Modular Approach to Aryl-<i>C</i>-ribonucleosides via the Allylic Substitution and Ring-Closing Metathesis Sequence. A Stereocontrolled Synthesis of All Four α-/β- and <scp>d</scp>-/<scp>l</scp>-<i>C</i>-Nucleoside Stereoisomers
作者:Jan Štambaský、Vojtěch Kapras、Martin Štefko、Ondřej Kysilka、Michal Hocek、Andrei V. Malkov、Pavel Kočovský
DOI:10.1021/jo201110z
日期:2011.10.7
generated from (S)-5a, with the enantiopure allylic carbonates (R)-9a,b has been developed as the key step in a new approach to C-nucleoside analogues. The anomeric center was thus constructed via a stereocontrolled formation of the C–O rather than C–C bond with retention of configuration. The resulting bisallyl ethers 15a,b (≥90% de and >99% ee) were converted into C-ribosides 29a,b via the Ru-catalyzed
(S)-5a生成的对映纯单保护的铜(I)对映体的铱(I)催化与对映纯烯丙基碳酸酯(R)-9a,b的烯丙基化反应已成为开发C的新方法的关键步骤-核苷类似物。因此,异头物中心是通过立体控制形成的C–O而非C–C键并保留构型而构建的。将所得的双烯丙基醚15a,b(de≥90%,ee≥99 %)转化为C-核苷29a,b通过Ru催化的闭环复分解,然后由OsO 4或RuO 4催化的非对映选择性二羟基化和脱保护。起始片段5a和9a,b的绝对构型的变化允许所有四个α/β- d / l-组合的立体控制合成。