Synthesis of Secondary and Tertiary Alkyl Boronic Esters by <i>gem</i>
-Carboborylation: Carbonyl Compounds as Bis(electrophile) Equivalents
作者:Dunfa Shi、Lu Wang、Chungu Xia、Chao Liu
DOI:10.1002/anie.201804684
日期:2018.8.6
tertiary alkyl boronic esters. The addition of B2pin2 to a carbonyl compound generates α‐oxyl‐substituted alkyl boron species. Organolithium and Grignard reagents are then applied as C nucleophiles for the 1,2‐metalate rearrangement process. The organolithium reagents can also be generated by C−H lithiation or halogen/lithium exchange. The use of chiral ligands led to the generation of chiral alkyl boronic
Deoxygenative Haloboration and Enantioselective Chloroboration of Carbonyls
作者:Dong Wang、Jun Zhou、Zihao Hu、Tao XU
DOI:10.1021/jacs.2c11024
日期:2022.12.21
α-haloboronates. Meanwhile, the difficult-to-obtain tertiary α-haloboronates can be also readily prepared via the same strategy with ketones. Furthermore, enantioselective chloroboration of carbonyls was successfully achieved to give chiral secondary or tertiary α-chloroboronates, the important intermediates to access enantioenrich multisubstituted stereocenters. These versatile products can be surprisingly attained
Copper-Catalyzed Diboration of Ketones: Facile Synthesis of Tertiary α-Hydroxyboronate Esters
作者:Melissa L. McIntosh、Cameron M. Moore、Timothy B. Clark
DOI:10.1021/ol100468f
日期:2010.5.7
The diboration of ketones with the (ICy)CuOt-Bu catalyst was developed to provide access to tertiary alpha-hydroxyboronate esters. The (ICy)CuOt-Bu catalyst was generated in situ with (ICy)CuCI and NaOt-Bu to afford a more efficient catalyst than the preformed (ICy)CuOt-Bu. These conditions result in the diboration of various ketones in toluene at 50 degrees C in 2-22 h. Treatment of the resulting products with silica gel affords the corresponding a-hydroxyboronate esters.
Stereoselective Formation of Trisubstituted Vinyl Boronate Esters by the Acid-Mediated Elimination of α-Hydroxyboronate Esters
作者:Weiye Guan、Alicia K. Michael、Melissa L. McIntosh、Liza Koren-Selfridge、John P. Scott、Timothy B. Clark
DOI:10.1021/jo500773t
日期:2014.8.1
trisubstituted vinyl boronate esters with moderate to good yields and selectivity. Addition of tosic acid to the crude diboration products provides the corresponding vinyl boronate esters upon elimination. The trisubstituted vinyl boronate esters are formed as the (Z)-olefin isomer, which was established by subjecting the products to a Suzuki–Miyaura coupling reaction to obtain alkenes of known geometry
铜催化酮的二硼化,然后是酸催化的消除,导致形成 1,1-二取代和三取代乙烯基硼酸酯,具有中等至良好的产率和选择性。将甲苯磺酸加入粗二硼化产物中,消除后得到相应的硼酸乙烯酯。三取代的乙烯基硼酸酯形成为 ( Z )-烯烃异构体,这是通过将产物进行 Suzuki-Miyaura 偶联反应以获得已知几何形状的烯烃来建立的。
Synthesis of α‐Seleno Boronates <i>via</i> Diboration of Carbonyl Compounds
作者:Sufal Paul、Rahul Mondal、K. Geetharani
DOI:10.1002/asia.202300761
日期:2023.11.16
We demonstrated the first sequential synthesis of gem-selenoborylation via the diboration of aldehydes and ketones. The selenation of the α-oxyl alkyl boronates was successfully achieved providing a series of synthetically valuable α-seleno alkyl boronates with good functional group tolerance.