Exploiting Alkylquinone Tautomerization for the Total Synthesis of Calothrixin A and B
作者:Luis M. Mori-Quiroz、Madeline M. Dekarske、Austin B. Prinkki、Michael D. Clift
DOI:10.1021/acs.joc.7b02101
日期:2017.12.1
The pentacyclic alkaloid calothrixin B (1) has been synthesized in 5 steps from murrayaquinone A (9). The key step involved the union of boryl aniline 31 with brominated murrayaquinone A (26). In this transformation, alkylquinone 26 undergoes tautomerization to a quinone methide, which is intercepted by boryl aniline 31 to forge a new C–N bond. An intramolecular Suzuki coupling, followed by dehydrogenative
2-{2-[(4-Methoxyphenoxy)methyl]phenyl}-4,4,5,5-tetramethyl-1,3,2-dioxaborolane and N-(4-Ethoxybenzyl)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzenamine: Molecular Structures Determined by Quantum-Chemical Calculations, NMR Spectroscopy, and X-Ray Diffraction Analysis
2-2-[(4-methoxyphenoxy)methyl]phenyl}-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (A) and N-(4-methoxybenzyl)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzenamine (B), have been synthesized and their single crystals grown from hexane and petroleum ether. The conformation analysis data demonstrate that the molecular structure optimized by DFT is consistent with the crystalstructure determined by X-ray
摘要 两种苯基硼酸酯衍生物,2-2-[(4-甲氧基苯氧基)甲基]苯基}-4,4,5,5-四甲基-1,3,2-二氧硼杂环戊烷( A )和N- (4-甲氧基苄基)-已合成2-(4,4,5,5-四甲基-1,3,2-二氧硼杂环戊烷-2-基)苯胺( B ),并从己烷和石油醚中生长出单晶。构象分析数据表明,DFT优化后的分子结构与X射线单晶衍射确定的晶体结构一致。对其分子静电势、Hirshfeld 表面分析和二维指纹进行了研究,揭示了化合物的一些物理和化学性质。
Synthesis of Pyridobenzazepines Using a One-Pot Rh/Pd-Catalyzed Process
作者:Heather Lam、Jennifer Tsoung、Mark Lautens
DOI:10.1021/acs.joc.7b00568
日期:2017.6.16
In recent years, our group has been developing Multicatalytic reactions for the synthesis of biologically relevant heterocyclic compounds. An efficient dual-metal catalyzed reaction of electron-deficient o-chlorovinylpyridines with o-aminophenylboronic esters to access pyridobenzazepines is described. Combining a Rh-I-catalyzed arylation followed by a Pd-catalyzed C-N coupling, in a one-pot procedure, provides a simplified method to access heterocycles without workup and purification after each step. The substrate scope encompasses a variety of N-H and N-alkylated pyridobenzazepine variants with yields up to 93%.