A novel procedure for the synthesis of C2‐diversified oxazoles, through palladium‐catalyzed imidoylative cyclization of α‐isocyanoacetamides with aryl, vinyl, alkynyl halides, or triflates, was developed. Migratory insertion of isocyanide into a C‐palladium(II) intermediate in a cascade process was also realized, generating alkyl‐substituted oxazoles. Therefore, oxazoles functionalized at the C2 position
A new, wide ranging, synthetically powerful, catalytic tandem cyclisation-anion capture process is proposed which depends on the rate of cyclisation of an organopalladium specifies (RPdX) onto a proximate alkene or diene being significantly faster than anion exchange and reductive elimination in the sequence RPdX → RPdY → RY + Pd(0). The catalytic cyclisation - anion capture sequence is illustrated
Palladium-Catalyzed Enantioselective Domino Heck–Cyanation Sequence: Development and Application to the Total Synthesis of Esermethole and Physostigmine
An efficient synthesis of functionalized 3-alkyl-3-cyanomethyl-2-oxindole 1 by a palladium-catalyzed domino Heck-cyanation reaction has been developed. Reaction of ortho-iodoanilide 5 with potassium ferro(II)cyanide, K(4)[Fe(CN)(6)], dissolved in DMF in the presence of palladium acetate and sodium carbonate afforded oxindole 1 in good to excellent yields. An enantioselective domino Heck-cyanation process
A catalytic enantioselective domino Heck carbonylation reaction of o-iodoacrylanilides with phenylacetylenes or water has been developed using a Pd/(Cu) catalytic system containing a chiral diphosphine ligand L9, furnishing a wide array of chiral β-carbonylated 3,3-disubstituted oxindoles in high yields with up to 99 % ee values.
The first Pd‐catalyzed domino Heck/phosphorylation of N‐(2‐iodophenyl)acrylamides with secondary phosphine oxides has been developed. The use of PdCl2 as a catalyst, 1,4‐bis(diphenylphosphino)butane as a ligand, K2CO3 as a base, various N‐(2‐iodophenyl)acrylamide derivatives are tolerant in this transformation, affording 3‐phosphinomethyl 3,3‐disubstituted oxindole products in good to excellent yields
N-(2-碘苯基)丙烯酰胺与仲膦氧化物的第一个Pd催化的多米诺Heck /磷酸化反应已经开发出来。在此转化过程中可以耐受使用PdCl 2作为催化剂,1,4-双(二苯基膦基)丁烷作为配体,K 2 CO 3作为碱,各种N-(2-碘苯基)丙烯酰胺衍生物,从而获得3-膦基甲基3,3-二取代的羟吲哚产品,收率良好至优异。这一转变为一步一步形成新的C-C和P-C键,羟吲哚环提供了一条直接途径。而且,该方法可轻松适用于大规模制备。