Diastereoselective Aminooxygenation and Diamination of Alkenes with Amidines by Hypervalent Iodine(III) Reagents

Abstract

Diastereoselective anti-aminooxygenation and anti-diamination of alkenes with amidines were enabled by hypervalent iodine(III) reagents such as PhI(OCOR)2 and PhI(NMs2)2, respectively. The present transformation offers diastereochemically pure dihydroimidazoles divergently from E- and Z-alkenes.

Recent Advances in the Synthesis of Imidazolines (2009–2020)

“…In the same year, Chen et al reported a hypervalent iodine-mediated diastereoselective anti-aminooxygenation and anti-diamination of alkenes with amidines to synthesize 2-imidazolines (Scheme 73). [74] Initial in- vestigations to obtain suitable conditions were performed by using a few hypervalent iodine(III) reagents (PhI(OCOCH 3 ) 2 , PhI(OCOCF 3 ) 2 , PhI(OCOPh) 2 ) with the amidine (R 1 , R 2 , R 3 = Ph; R 4 , R 5 = H) (258) in different solvents. Both bis-acetate and bis-trifluoroacetate containing iodine reagents worked efficiently in dichloromethane.…”

Oxidative Heterocycle Formation Using Hypervalent Iodine(III) Reagents

“…Analogously, in 2014, Chiba and coworkers reported an efficient hypervalent iodine enabled diastereoselective anti-aminooxygenation and anti-diamination of N-allylamidines 20 for the synthesis of dihydroimidazoles 21 [22]. Zhu and coworkers [23] developed a metal-free intramolecular C-H amination reaction of N-aryl-2-aminopyridines 22 catalyzed by a hypervalent iodine(III) species generated in situ from iodobenzene and peracetic acid for the synthesis of pyrido[1,2-a]benzimidazoles 23 (Scheme 5).…”

Recent Advances in Intramolecular Metal‐Free Oxidative C–H Bond Aminations Using Hypervalent Iodine(III) Reagents

“…Chiba group developed PIDA ( 1 ) mediated method for diastereoselective anti ‐aminooxygenation of alkenes with amidines 194 to produce dihydroimidazoles 195 divergently from E ‐ and Z ‐alkenes (Scheme a) . The hypervalent iodine(III) reagent PIFA ( 2 ) was used to accelerate the reaction with amidine 194 , leading to full conversion anti ‐aminohydroxylation product 196 in 82 % yield.…”