Iron-catalyzed sulfonylimine synthesis under neutral conditions

Iron Catalysis in Organic Synthesis

“…999 The reaction of aldehydes with arylboronic acids under aerobic conditions, using iron(II) triflate as catalyst in the presence of an NHC ligand and potassium tert-butoxide as base, led to carboxylic esters (Scheme 559). 1000 On the basis of mechanistic experiments it was assumed that phenolic species are formed from the arylboronic acids which undergo oxidative esterification with the aldehyde.…”

N‐Heterocyclic Carbene Piano‐Stool Iron Complexes as Efficient Catalysts for Hydrosilylation of Carbonyl Derivatives

“…[17,18] Our interest in iron catalysis [19] and especially hydrosilylation [20,21] prompted us to examine the possibility of using NHC well-defined iron complexes in the hydrosilylation reaction. The report by Nikonov [22] using cationic [CpFe(phosphine)] complexes and the pioneer works from Brunner [23] oriented us towards piano-stool iron carbene complexes to catalyze such reduction reactions.…”

Facile Synthesis of N-Tosyl Aza-Baylis-Hillman Adducts of Acrylamide via a Pd-Catalyzed Hydration of Nitrile to Amide

“…One is the synthesis of N-tosylimine and DABCOcatalyzed Baylis-Hillman reaction with acrylonitrile. 1,7,8 The other way involved the preparation of the acetate of BaylisHillman adduct of acrylonitrile 1a and the conversion of the acetate group into N-tosyl group via the corresponding DABCO salt, as reported in the literature. 9 The first approach did not produce desired N-tosyl aza-Baylis-Hillman adduct 2a in a pure form due to the partial hydrolysis of N-tosylimine to the corresponding aldehyde and tosylamide, thus Baylis-Hillman adduct 1a was contaminated in a variable amounts depending upon the substrate (Scheme 2).…”

“…9 With these starting materials 2a-i, we examined a Pd-catalyzed hydration under the influence of Pd(OAc) 2 (10 mol %), PPh3 (20 mol %), CH3CH=NOH (2.0 equiv) in refluxing aqueous EtOH for 3 h, 4 and the results are summarized in Table 1. As shown in Table 1, various kinds of N-tosyl azaBaylis-Hillman adducts of acrylamide 3a-g were synthesized in good yields (83 ~ 91%), as shown in entries [1][2][3][4][5][6][7]. N-Methanesulfonyl derivative 2h and N-phthalyl analog 2i showed similar reactivity (entries 8 and 9).…”