Iodine(III)-mediated aromatic amidation vs olefin amidohydroxylation. The amide N-substituent makes the difference

Iron Catalyzed Asymmetric Oxyamination of Olefins

“…1, 2 Nevertheless, the poor regioselectivity of this reaction 3 and the requirement for a toxic and precious osmium catalyst has inspired significant efforts over the last decade to design alternative oxyamination processes based on palladium, 4 platinum, 5 rhodium, 6 gold, 7 copper, 8 hypervalent iodine, 9 and radical reactions. 10 Several enantioselective osmium-free oxyaminations have been reported in an intramolecular context.…”

Phenyliodine(III) Bis(trifluoroacetate)

“…Selectivity is dictated by the N-substituent, methoxy or paramethoxyphenyl (eq 26). 32 The authors propose that when treated with PIFA the N-substituted acetamide affords a stabilized N-acylnitrenium intermediate. However in the case of the PMP group, sterics dictate that cyclization occur on the ally group to afford an intermediate pyrrolidinone via an olefin aminohydroxylation mechanism.…”

Polyvalent iodine in organic chemistry: Recent developments, 2002–2005

“…N-acylnitrenium intermediates SCHEME 9 SCHEME 10 SCHEME 11 generated by the action on properly substituted amides exerts a selective control to afford either quinolin-2-ones or pyrrolidin-2-ones in good yields and complete selectivity [46,47]. The cyclization process can take two different pathways depending on the nature of the amide N-substituent to afford either quinoline or pyrrolidine skeletons (Scheme 15).…”

“…This synthesis involves a heteroatom transfer reaction between 1-alkynyl(phenyl)-λ3-iodanes and diphenyl chalcogens under mild conditions. In this reaction, the 1-alkynyl group of the λ3-iodanes was selectively transferred to the chalcogen atom in preference to the phenyl group [85] (Schemes [46][47][48].…”