77364-02-4Relevant academic research and scientific papers
Enantioselective Aza-Heck Cyclizations of N-(Tosyloxy)carbamates: Synthesis of Pyrrolidines and Piperidines
Ma, Xiaofeng,Hazelden, Ian R.,Langer, Thomas,Munday, Rachel H.,Bower, John F.
supporting information, p. 3356 - 3360 (2019/03/07)
Pd(0)-systems modified with SPINOL-derived phosphoramidate ligands promote highly enantioselective aza-Heck cyclizations of alkenyl N-(tosyloxy)carbamates. The method provides versatile access to challenging N-heterocycles and represents the broadest scope enantioselective aza-Heck protocol developed to date.
Stereospecific Alkene Aziridination Using a Bifunctional Amino-Reagent: An Aza-Prilezhaev Reaction
Farndon, Joshua J.,Young, Tom A.,Bower, John F.
supporting information, p. 17846 - 17850 (2019/01/04)
In situ deprotection (TFA) of O-Ts activated N-Boc hydroxylamines triggers intramolecular aziridination of N-tethered alkenes to provide complex N-heterocyclic ring systems. Synthetic and computational studies corroborate a diastereospecific aza-Prilezhaev-type mechanism. The feasibility of related intermolecular alkene aziridinations is also demonstrated.
A reductive coupling strategy towards ripostatin A
Schleicher, Kristin D.,Jamison, Timothy F.
supporting information, p. 1533 - 1550 (2013/10/22)
Synthetic studies on the antibiotic natural product ripostatin A have been carried out with the aim to construct the C9-C10 bond by a nickel(0)-catalyzed coupling reaction of an enyne and an epoxide, followed by rearrangement of the resulting dienylcyclopropane intermediate to afford the skipped 1,4,7-triene. A cyclopropyl enyne fragment corresponding to C1-C9 has been synthesized in high yield and demonstrated to be a competent substrate for the nickel(0)-catalyzed coupling with a model epoxide. Several synthetic approaches toward the C10-C26 epoxide have been pursued. The C13 stereocenter can be set by allylation and reductive decyanation of a cyanohydrin acetonide. A mild, fluoride-promoted decarboxylation enables construction of the C15-C16 bond by an aldol reaction. The product of this transformation is of the correct oxidation state and potentially three steps removed from the targeted epoxide fragment.
Synthesis of the C1-C5 and C6-C24 fragments of the RNA polymerase inhibitors ripostatin A and B
Kujat, Christof,Bock, Martin,Kirschning, Andreas
, p. 419 - 422 (2007/10/03)
The enantioselective synthesis of the C1-C5 and C6-C24 fragments of the ripostatins utilize a Negishi coupling, two Nagao acetate aldol reactions followed by a Denmark vinylogous aldol reaction and Stille couplings as key C-C bond forming steps. Georg Thi
Synthetic Studies of Fungal Metabolites: Ascofuranone and Colletochlorin D
Guthrie, Anne E.,Semple, Edward J.,Joullie, Madeleine M.
, p. 2369 - 2376 (2007/10/02)
Procedures have been developed for the synthesis of hexasubstituted aromatic rings which are present in many fungal metabolites such as ascofuranone and colletochlorin D. (3-Bromo-5-chloro-2,6-dimethoxy-p-tolyl)acetaldehyde was synthesized from orcinol in eight steps.This aldehyde was converted to 2-bromo-6-chloro-3,5-dimethoxy-4-(3-methyl-2-butenyl)toluene which was subsequently formylated to afford 3-chloro-4,6-dimetoxy-2-methyl-5-(3-methyl-2-butenyl)benzaldehyde.Although various demethylation procedures were tried, demethylation of both methoxy groups could not be accomplished.In our attempts to synthesize ascofuranone, (3-bromo-5-chloro-2,6-dimethoxy-p-tolyl)acetaldehyde was treated with isopropenylmagesium bromide to afford an unsteble allylic alcohol which was immediately subjected to the conditions of the "orthoacetate Claisen rearrangement" to give 2-bromo-6-chloro-4-3,5-dimethoxytoluene.This compound was then converted to 2-bromo-6-chloro-3,5-dimethoxy-4-toluene bromide in three steps.All attempts to carry out a Wittig reaction between this compound and 6,6-dimethyl-1,4,7-trioxaspironon-8-yl methyl ketone failed.Other coupling methods were equally unsuccesful.
Synthesis of functionalized tetrahydrofurans
Semple, J.Edward,Guthrie, Anne E.,Joullie, Madeleine M.
, p. 4561 - 4564 (2007/10/02)
A novel cyclization reaction is described which affords readily manipulable 3(2H)-dihydrofuranone ethylene ketals, useful in the total synthesis of an ascofuranone model, bullatenone, and muscarine analogs.
