A highly selective C-H amination reaction under iron catalysis has been developed. This novel system, which employs an inexpensive, nontoxic [Fe(III)Pc] catalyst (typically used as an industrial ink additive), displays a strong preference for allylic C-H amination over aziridination and all other C-H bond types (i.e., allylic > benzylic > ethereal > 3° > 2° ≫ 1°). Moreover, in polyolefinic substrates
Ambruticins: tetrahydropyran ring formation and total synthesis
作者:James I. Bowen、Luoyi Wang、Matthew P. Crump、Christine L. Willis
DOI:10.1039/d1ob00883h
日期:——
the tetrahydropyran ring of the ambruticins is formed via the AmbJ catalysed epoxidation of the unsaturated 3,5-dihydroxy acid, ambruticin J, followed by regioselective cyclisation to ambruticin F. Herein, a convergent approach to the total synthesis of ambruticin J is described as well as model studies involving epoxidation and cyclisations of unsaturated hydroxy esters to give tetrahydropyrans and
Diverse<i>N</i>-Heterocyclic Ring Systems via Aza-Heck Cyclizations of<i>N</i>-(Pentafluorobenzoyloxy)sulfonamides
作者:Ian R. Hazelden、Xiaofeng Ma、Thomas Langer、John F. Bower
DOI:10.1002/anie.201605152
日期:2016.9.5
bond of N‐(pentafluoro‐benzoyloxy)sulfonamides are described. These studies, which encompass only the second class of aza‐Heck reaction developed to date, provide direct access to diverse N‐heterocyclicringsystems.
Pyrrolidines and Piperidines by Ligand-Enabled Aza-Heck Cyclizations and Cascades of <i>N</i>
-(Pentafluorobenzoyloxy)carbamates
作者:Ian R. Hazelden、Rafaela C. Carmona、Thomas Langer、Paul G. Pringle、John F. Bower
DOI:10.1002/anie.201801109
日期:2018.4.23
Ligand‐enabled aza‐Heck cyclizations and cascades of N‐(pentafluorobenzoyloxy)carbamates are described. These studies encompass the first examples of efficient non‐biased 6‐exo aza‐Heck cyclizations. The methodology provides direct and flexible access to carbamate protected pyrrolidines and piperidines.
The uncatalyzed intramolecular carbonyl ene (ICE) reaction of substituted ε,ζ-unsaturated α-keto esters to terpenoid-related building blocks has been studied. We found a beneficial effect of a silyl substituent at the ene segment on the kinetics of the ICE reaction. A generalizable and scalable synthesis of ε,ζ-unsaturated α-keto esters fromallylicalcohols was developed.