Unified Access to Pyrimidines and Quinazolines Enabled by N–N Cleaving Carbon Atom Insertion
作者:Ethan E. Hyland、Patrick Q. Kelly、Alexander M. McKillop、Balu D. Dherange、Mark D. Levin
DOI:10.1021/jacs.2c09616
日期:2022.10.26
transformations with the capacity to modify such molecular skeletons with modularity remain highly desirable. Ring expansions that enable interconversion of privileged heterocyclic motifs are especially interesting in this regard. As such, the known mechanisms for ring expansion and contraction determine the classes of heterocycle amenable to skeletal editing. Herein, we report a reaction that selectively cleaves
A facile metal-free one-flask synthesis of multi-substituted furans <i>via</i> a BF<sub>3</sub>·Et<sub>2</sub>O mediated formal [4 + 1] reaction of 3-chloro-3-phenyldiazirines and α,β-alkenyl ketones
A facile, efficient and metal free one-flask approach to diversely substituted furans from easily accessible 3-chloro-3-phenyldiazirines and α,β-alkenyl ketones is reported. This protocol integrates three steps of cyclopropanation, Cloke–Wilson rearrangement and elimination of HCl in one-flask to give products in moderate to good yields. It provides a metal and oxidant free approach to multi-substituted
Photochemically Mediated Ring Expansion of Indoles and Pyrroles with Chlorodiazirines: Synthetic Methodology and Thermal Hazard Assessment
作者:Ben W. Joynson、Graham R. Cumming、Liam T. Ball
DOI:10.1002/anie.202305081
日期:2023.8
demonstrate that pyridinium and quinolinium salts can be accessed by the insertion of a single C-atom from an arylchlorodiazirine into the parent N-alkyl pyrrole or indole. The azinium products of ringexpansion are activated towards oxygenation and hydrogenation, expediting further structural diversification. Safer methods for the use of diazirines as carbene precursors have been developed with insight
我们证明,吡啶盐和喹啉盐可以通过将芳基氯二嗪中的单个 C 原子插入母体 N-烷基吡咯或吲哚来获得。扩环的氮化产物被激活,进行氧化和氢化,加速了进一步的结构多样化。利用差示扫描量热法的洞察力,已经开发了使用二嗪嗪作为卡宾前体的更安全的方法。
Carbon Atom Insertion into Pyrroles and Indoles Promoted by Chlorodiazirines
作者:Balu D. Dherange、Patrick Q. Kelly、Jordan P. Liles、Matthew S. Sigman、Mark D. Levin
DOI:10.1021/jacs.1c06287
日期:2021.8.4
calculations supporting a selectivity-determining cyclopropanation step. Computations surprisingly indicate that the stereochemistry of cyclopropanation is of little consequence to the subsequent electrocyclicringopening that forges the pyridine core, due to a compensatory homoaromatic stabilization that counterbalances orbital-controlled torquoselectivity effects. The utility of this skeletal transform is
Cyclopropanation of Alkenes with Halodiazirines as Halocarbene Precursors in Continuous Flow
作者:Hoang‐Minh To、Thierry Ollevier
DOI:10.1002/chem.202303969
日期:——
The preparation of substituted 3-chloro-3-aryl-cyclopropanes through the reaction of alkenes with photolytically-generated chlorocarbenes from chlorodiazirines is reported as an effective method. This approach facilitates the production of diverse 3-chloro-3-aryl-cyclopropanes (32 examples) in an continuousflow with a residence time of 5 minutes under the influence of light-emitting diode (LED) irradiation