Radical–Radical Cyclization Cascades of Barbiturates Triggered by Electron-Transfer Reduction of Amide-Type Carbonyls
作者:Huan-Ming Huang、David J. Procter
DOI:10.1021/jacs.6b04086
日期:2016.6.22
radical-radical cyclizationcascades. An alternative fragmentation-radical cyclization sequence of related substrates allows access to bicyclic uracil derivatives. The radical-radical cyclizationprocess constitutes the first example of a radical cascade involving ET reduction of the amide carbonyl. Products of the cascade can be readily manipulated to give highly unusual and medicinally relevant bi-
自由基-自由基环化级联由 SmI2-H2O 向酰胺型羰基的单电子转移触发,一步将简单的非手性巴比妥酸盐转化为含半胺或烯胺的三环支架,其中含有多达五个连续的立体中心(包括四元立体中心)。此外,我们描述了 LiBr 对最具挑战性的自由基 - 自由基环化级联的惊人有益影响。相关底物的另一种断裂-自由基环化序列允许获得双环尿嘧啶衍生物。自由基-自由基环化过程构成了涉及酰胺羰基 ET 还原的自由基级联的第一个例子。级联产物可以很容易地得到非常不寻常和医学上相关的双环和三环巴比妥酸盐。
Cascade Reaction of Alkynols and 7-Oxabenzonorbornadienes Involving Transient Hemiketal Group Directed C–H Activation and Synergistic Rh<sup>III</sup>/Sc<sup>III</sup> Catalysis
作者:Deng Yuan Li、Liang Liang Jiang、Shuang Chen、Zheng Lu Huang、Li Dang、Xin Yan Wu、Pei Nian Liu
DOI:10.1021/acs.orglett.6b02587
日期:2016.10.7
As the first cascade C–Hactivationdirected by a transient group, reaction of alkynols and 7-oxabenzonorbornadienes has been achieved via synergistic rhodium and scandium catalysis to afford spirocyclic dihydrobenzo[a]fluorenefurans. This transformation proceeds by a transient hemiketal group directedC–Hactivation, dehydrative naphthylation, and intramolecular Prins-type cyclization. Mechanistic
作为由一个瞬态基团控制的第一个级联C–H活化,炔醇与7-氧杂苯并降冰片二烯的反应已通过协同的铑和scan催化作用而得到,以提供螺环二氢苯并[ a ]芴呋喃。这种转化是通过一个半胱氨酸基团直接引导C–H活化,脱水萘化和分子内Prins型环化而进行的。机理研究和密度泛函理论计算表明,决定速率的步骤是C–H键断裂,瞬态半酮基和协同Rh III / Sc III催化均起关键作用。
Leveraging the <i>Halo</i>-Nazarov Cyclization for the Chemodivergent Assembly of Functionalized Haloindenes and Indanones
作者:Connor Holt、Georgios Alachouzos、Alison J. Frontier
DOI:10.1021/jacs.9b00198
日期:2019.4.3
In this report, we describe a halo-Prins/aryl halo-Nazarov cyclization strategy that employs readily available starting materials, inexpensive reagents, and convenient reaction procedures to generate functionalized haloindenes and indanones. The scope and limitations of the method are outlined, demonstrating that aromatic systems readily react under mild, catalytic conditions when this strategy is
Gold(I)/Chiral Brønsted Acid Catalyzed Enantioselective Hydroamination-Hydroarylation of Alkynes: The Effect of a Remote Hydroxyl Group on the Reactivity and Enantioselectivity
作者:Valmik S. Shinde、Manoj V. Mane、Kumar Vanka、Arijit Mallick、Nitin T. Patil
DOI:10.1002/chem.201405061
日期:2015.1.12
range of pyrrole‐based aromatic amines to give pyrrole‐embedded aza‐heterocyclic scaffolds bearing a quaternary carbon center. The presence of a hydroxylgroup in the alkyne tether turned out to be very crucial for obtaining products in high yields and enantioselectivities. The mechanism of enantioinduction was established by carefully performing experimental and computational studies.
Targeting an Aromatic Hotspot in <i>Plasmodium falciparum</i>
1-Deoxy-<scp>d</scp>
-xylulose-5-phosphate Reductoisomerase with β-Arylpropyl Analogues of Fosmidomycin
作者:Sanjeewani Sooriyaarachchi、René Chofor、Martijn D. P. Risseeuw、Terese Bergfors、Jenny Pouyez、Cynthia S. Dowd、Louis Maes、Johan Wouters、T. Alwyn Jones、Serge Van Calenbergh、Sherry L. Mowbray
DOI:10.1002/cmdc.201600249
日期:2016.9.20
growth of Plasmodium spp. Fosmidomycin [(3-(N-hydroxyformamido)propyl)phosphonic acid, 1] and its acetyl homologue FR-900098 [(3-(N-hydroxyacetamido)propyl)phosphonic acid, 2] potently inhibit 1-deoxy-d-xylulose-5-phosphate reductoisomerase (Dxr), a key enzyme in this biosynthetic pathway. Arylpropyl substituents were introduced at the β-position of the hydroxamate analogue of 2 to study changes in