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The first metal-free catalytic intermolecular enantioselective Michael addition to unactivated α,β-unsaturated amides is described. Consistently high enantiomeric excesses and yields were obtained over a wide range of alkyl thiol pronucleophiles and elect

A catalytic asymmetric conjugate hydrophosphination of α,β-unsaturated amides is accomplished by virtue of the strong nucleophilicity of copper(I)-PPh2 species, which provides an array of chiral phosphines bearing an amide moiety in high to excellent yields with excellent enantioselectivity. Furthermore, the dynamic kinetic resolution of unsymmetrical diarylphosphines (HPAr1Ar2) is successfully carried out through the copper(I)-catalyzed conjugate addition to α,β-unsaturated amides, which affords P-chiral phosphines with good-to-high diastereoselectivity and high enantioselectivity. 1H NMR studies show that the precoordination of HPPh2 to copper(I)-bisphosphine complex is critical for the efficient deprotonation by Barton's Base. Moreover, the relative stability of the copper(I)-(R,RP)-TANIAPHOS complex in the presence of excessive HPPh2, confirmed by 31P NMR studies, is pivotal for the high asymmetric induction, as the ligand exchange between bisphosphine and HPPh2 would significantly reduce the enantioselectivity. At last, a double catalytic asymmetric conjugate hydrophosphination furnishes the corresponding product in high yield with high diastereoselectivity and excellent enantioselectivity, which is transformed to a chiral pincer palladium complex in moderate yield. This chiral palladium complex is demonstrated as an excellent catalyst in the asymmetric conjugate hydrophosphination of chalcone.

Here we report that readily available silyl- and boron-based Lewis acids in combination with chiral copper catalysts are able to overcome the reactivity issues of unactivated enamides, known as the least reactive carboxylic acid derivatives, toward alkyla

1,3-Dipolar cycloaddition is a commonly exploited method to access 5-membered chemical entities with a variety of peripheral functionalities and their stereochemical arrangements. Nitrones are isolable 1,3-dipoles that exhibit sufficient reactivity toward electron-deficient olefins in the presence of Lewis acids to deliver highly substituted isoxazolidines. Herein we document that α,β-unsaturated amides, generally regarded as barely reactive in a 1,3-dipolar reaction manifold, were effectively activated using the designed 7-azaindoline auxiliary in an In(OTf)3/bishydroxamic acid catalytic system. The broad substrate scope and clean removal of the 7-azaindoline auxiliary from the product highlight the synthetic utility of the present catalysis.

Figure Persented: N-Isopropyl acrylamide (NIPAM), N,N-dimethyl acrylamide (DMAA), and 2-acetamidoethyl acrylate (AcAMEA) were copolymerized with ethylene employing [(P∧O)PdMe(DMSO)] (1-DMSO; P∧O = κ2-P,O- Ar2PC6H4SO2O with Ar = 2-MeOC 6H4) as a catalyst precursor. Inhibition studies with nonpolymerizable polar additives show that reversible κ-O-coordination of free amide retards polymerization significantly. Retardation of polymerization increases in the order ethyl acetate ? methyl ethyl sulfone 6H11NO 2)nMe] (n ≤ 3), as determined by electrospray ionization mass spectrometry. The solid-state structure of the methanol adduct of the 2,1-insertion product of NIPAM into 1-DMSO, [(P∧O) Pd{η1-CH(CONHiPr)CH2CH3} (κ1-O-MeOD)] (2-MeOD), was determined by single crystal X-ray diffraction. Both 2,1- and 1,2-insertions of DMAA into the Pd-Me bond of a [(P∧O)PdMe] fragment occur to afford a ca. 4:1 mixture of chelates [(P∧O)Pd{κ2-C,O-C(CH2CH3)C(O)NMe 2}] (3) and [(P∧O)Pd{κ2-C,O-CH 2C(CH3)C(O)NMe2}] (4). The four-membered chelate of 3 is opened by coordination of 2,6-lutidine (3 + 2,6-lutidine ? 3-LUT) with ΔH° = -41.8(10.5) kJ and ΔS° = -115(37) J mol-1 K-1.

A catalyst composed of (R,R)-MeDuphos and CuBr·SMe2 catalyzes the addition of RMgBr (R = Et, C5H11, Ph) to simple enamides (E)-Me2NCOCH{double bond, long}CHR1 (R1 = Me, C5H1

Treatment of allylic and benzylic halides with N,N- dimethylcarbamoyl(trimethyl)silane in the presence of tetrakis- (triphenylphosphine)palladium(0) affords tertiary amides, which arise from the replacement of the halogen by the N,N-dimethylcarbamoyl group.

The invention relates to a method for production of α,β-unsaturated amide compounds of general formula (I): whereby (A) a protective group is introduced into a molecule of general formula (II) to give a compound of formula (III), (B) the compound obtained is reacted in the presence of (i) a dehydrogenation catalyst and (ii) a suitable oxidation agent and (C) the protective groups are removed.

The reactions of the silyllithium reagent with tertiary amides was discussed. The enediamines were easily isomerized from cis to trans, easily oxidized to dienediamines and were hydrolyzed to α-aminoketones. If the two equivalents of the silyllithium reagent were used, the product was an α-silylamine. The results show that each member of the homologous series of amides gives rise to a substantially different product.

The alkylation reactions of enolates derived from the highly diastereoselective conjugate additions of lithium (R)-N-benzyl-N-α-methylbenzylamide (R)-1 to N,N-dimethyl crotonamide 2 and N,N-dimethyl cinnamide 3 have been investigated.The alkylations of en

Chloroallyllitium and gem-chloro(methyl)allyllithium readly react, via conjugated addition and cyclisation, with α-ethylenic aliphatic tertiary amides to produce, in a "one-pot" reaction, alkyl-substituted 1-amido-2-vinylcyclopropanes.

An investigation of the base-catalyzed conjugative isomerization of a series of β,γ-unsaturated esters to their corresponding α,β-unsaturated esters was performed.It was found that, withh sodium hydride in THF, methyl 3-butenoate isomerized initially to a 5:1 ratio of (Z)- to (E)-methyl 2-butenoates; the Z:E ratio is time dependent, and after several days, the thermodynamic ratio 1:23 = Z:E was obtained.The isomerization appears to be catalytic in NaH, as it proceeds with less than 1 molar equiv of base, no hydrogen evolution is observed, and the reaction rate is approximately first order in NaH and zero order in ester.Under the same conditions (Z)-methyl 3-hexenoate isomerized stereoselectively to (E)-methyl 2-hexenoate while (E)-methyl 3-hexenoate isomerized to a 2:1 mixture of (Z)- and (E)-methyl 2-hexenoates.These product ratios are far from the isomeric compositions obtained under equilibrating conditions.To investigate further the stereochemical outcome of these isomerizations, three isomeric β,γ-unsaturated methyl esters were studied: (a) methyl 3-ethyl-3-butenoate isomerized exlusively to (E)-methyl 3-methyl-2-pentenoate; (b) (E)-methyl 3-methyl-3-pentenoate isomerized exlusively to (Z)-methyl 3-methyl-2-pentenoate; (c) (Z)-methyl 3-methyl-3-pentenoate isomerized exlusively to (E)-methyl 3-methyl-2-pentenoate.In the latter three cases, dimerization was not observed presumably due to steric effects.Related results were observed for a smaller series of β,γ-unsaturated amide isomerizations.Examination of the literature on olefin isomerizations reveals a general trend that the current results exemplify.Thus, in the absence of severe steric factors or cation-anion complexation, deprotonation at allylic positions kinetically preferentially forms the anion possessing a cisoid crotyl subunit (if available) regardless of initial substrate conformation.The stereochemical consequences of this results in E Z and Z E geometry conversions in kinetic 1,2-transpositions of olefins.This generalization can also be applied to the stereochemical results of ketone, ester, and hydrazone enolate formation, base-catalyzed exchange in polysubstituted aromatics and heteroaromatics, and other reactions involving the formation of allylic or benzylic anions.