58173-74-3Relevant academic research and scientific papers
Development of a Scalable Route for a Highly Polar Heterocyclic Aminocyclopropyl Building Block
Abele, Stefan,Ahmetovic, Muhamed,Fleischer, Tony,Sch?fer, Gabriel
supporting information, p. 1735 - 1742 (2020/10/26)
A robust and scalable route toward key heterocyclic building block 1-(pyrimidin-2-yl)cyclopropan-1-amine hydrochloride from cyclopropanated starting material 1-amino-1-cyclopropanecarbonitrile hydrochloride was successfully developed. The key to success was the construction of a pyrimidine ring via cyclization from an amidine intermediate and a bench-stable 2-chloro vinamidinium hexafluorophosphate salt. The cyclization was performed under mild conditions, and the resulting 4-cloropyrimidine derivative was isolated in high yield and purity. The final hydrogenation was intensively optimized: A combination of Pd(OH)2/C as a catalyst and NaOMe as a base at 1 bar H2 pressure in MeOH simultaneously cleaved the Cbz group and dechlorinated the pyrimidine ring while at the same time suppressing the over-reduction of the pyrimidine ring to below 1.0%. After acidification with HCl, followed by removal of the catalyst and NaCl by filtration, the final product was isolated in high yield and purity as a bench-stable off-white solid. The overall yield of the five-step sequence was 57%.
Scope of the inverse electron demand Diels-Alder reactions of 1,2,3-triazine
Anderson, Erin D.,Boger, Dale L.
supporting information; experimental part, p. 2492 - 2494 (2011/07/09)
Chemical equations presented. An examination of the scope of the inverse electron demand Diels-Alder reactions of the parent unsubstituted 1,2,3-triazine is described including the first report of its unique capabilities for participating in previously unexplored [4 + 2] cycloaddition reactions with heterodienophiles.
Inverse electron demand diels-alder reactions of 1,2,3-triazines: Pronounced substituent effects on reactivity and cycloaddition scope
Anderson, Erin D.,Boger, Dale L.
supporting information; experimental part, p. 12285 - 12292 (2011/09/16)
A systematic study of the inverse electron demand Diels-Alder reactions of 1,2,3-triazines is disclosed, including an examination of the impact of a C5 substituent. Such substituents were found to exhibit a remarkable impact on the cycloaddition reactivity of the 1,2,3-triazine without altering, and perhaps even enhancing, the intrinsic cycloaddition regioselectivity. The study revealed not only that the reactivity may be predictably modulated by a C5 substituent (R = CO2Me > Ph > H) but also that the impact is of a magnitude to convert 1,2,3-triazine (1) and its modest cycloaddition scope into a heterocyclic azadiene system with a reaction scope that portends extensive synthetic utility, expanding the range of participating dienophiles. Significantly, the studies define a now powerful additional heterocyclic azadiene, complementary to the isomeric 1,2,4-triazines and 1,3,5-triazines, capable of dependable participation in inverse electron demand Diels-Alder reactions, extending the number of complementary heterocyclic ring systems accessible with implementation of the methodology.
Negishi coupling of secondary alkylzinc halides with aryl bromides and chlorides
Han, Chong,Buchwald, Stephen L.
supporting information; experimental part, p. 7532 - 7533 (2009/10/16)
(Chemical Equation Presented) An efficient palladium-catalyzed process has been developed for Negishi coupling of secondary alkylzinc halides with a wide range of aryl bromides and activated aryl chlorides. A palladium catalyst composed of a new biaryldialkylphosphine ligand, CPhos, effectively promotes the rate of the reductive elimination step relative to the rate of the undesired β-hydride elimination. The broad substrate scope and excellent ratio of the desired secondary to the undesired primary coupling product make this method a powerful and reliable tool forC(sp3)-C(sp2) bond formation.
