A Practical Ruthenium-Catalyzed Cleavage of the Allyl Protecting Group in Amides, Lactams, Imides, and Congeners
作者:Benito Alcaide、Pedro Almendros、Jose M. Alonso
DOI:10.1002/chem.200501227
日期:2006.3.20
deprotection of N-allylic amide-like moieties was developed. The first examples accounting for the ruthenium-catalyzed deallylation of amides, lactams, imides, pyrazolidones, hydantoins, and oxazolidinones have been achieved by the sequential use of Grubbs carbene (isomerization step) and RuCl(3) (oxidation step). A variety of substrates, including enantiopure multifunctional beta- and gamma-lactams, can
Cascade of the Hinsberg / IMDAF reactions in the synthesis 2-arylsulfonyl-3a,6-epoxyisoindoles and 4a,7-epoxyisoquinolines in water
作者:Maryana A. Nadirova、Anastasia V. Khanova、Fedor I. Zubkov、Dmitriy F. Mertsalov、Irina A. Kolesnik、Sergey K. Petkevich、Vladimir I. Potkin、Anton A. Shetnev、Sofia I. Presnukhina、Anna A. Sinelshchikova、Mikhail S. Grigoriev、Vladimir P. Zaytsev
DOI:10.1016/j.tet.2021.132032
日期:2021.4
formation of a 3a,6-epoxyisoindole core in one synthetic stage. Usually, in boiling water, the interaction sequence involves two consecutive steps: the Hinsberg reaction and the intramolecular Diels–Alder furanе (IMDAF) reaction. The scope and limitations of the proposed method were thoroughly investigated, and it was revealed that the key [4 + 2] cycloaddition step proceeds through an exo-transition state
5-aminoisoxazolines via tandem catalytic isomerization (of N-allyl systems to N-(1-propenyl) systems)—1,3-dipolar cycloaddition (of a stable nitrileoxide to N-(1-propenyl) systems) is presented. Rhodium and ruthenium complexes, Verkade’s superbase, and 18-crown-6/KOH system were used for the syntheses of the N-(1-propenyl) systems. 4-P-substituted isoxazoline was also synthesized via cycloaddition of
Cucurbit[7]uril as a Supramolecular Artificial Enzyme for Diels-Alder Reactions
作者:Aniello Palma、Markus Artelsmair、Guanglu Wu、Xiaoyong Lu、Steven J. Barrow、Najib Uddin、Edina Rosta、Eric Masson、Oren A. Scherman
DOI:10.1002/anie.201706487
日期:2017.12.4
mimic the activity of natural enzymes using supramolecular constructs (artificial enzymes) is a vibrant scientific research field. Herein, we demonstrate that cucurbit[7]uril (CB[7]) can catalyseDiels–Alderreactions for a number of substituted and unreactive N‐allyl‐2‐furfurylamines under biomimetic conditions, without the need for protecting groups, yielding powerful synthons in previously unreported
Rapid construction of tetrahydropyridine scaffolds <i>via</i> formal imino Diels–Alder reactions of Schiff bases and Nazarov reagents
作者:Yen-Ku Wu、Viresh H. Rawal
DOI:10.1039/c9ob01880h
日期:——
Described is a one-flask, two-step method for the synthesis of highly functionalized piperidines. The process involves formal [4 + 2] cycloadditions of Schiffbases and Nazarov reagents, followed by facile elaborations of the initial cycloadducts. Notably, these aza-annulations are facilitated by protic solvents and proceed smoothly under ambient conditions, without other additives. The synthetic utility