Sugata Chatterjee

Palladium-catalyzed acylation of organozincs and other organometallics as a convenient route to ketones☆

Abstract The reaction of organozincs with acyl chlorides catalyzed by palladium-phosphine complexes, e.g., Pd(PPh 3 ) 4 , provides a highly general and convenient route to ketones.

Scope of the palladium-catalyzed coupling reaction of organometallics with allylic electrophiles. Effect of the leaving group☆

Various allyl alcohol derivatives containing OAlR2, OPO(OR)2, and OSiR3 groups, in addition to allylic halides and acetates, participate in the Pd-catalyzed coupling reaction with alkenyl- and arylmetals, such as those containing Al, Zn and Zr.to give the corresponding cross-coupled products, the order of their reactivity being: halogen, OAc > OAlR2 > OPO(OR)2 > OSiR3.

Highly regioselective generation of “thermodynamic” enolates and their direct characterization by NMR☆

Addition of 2-methylcyclohexanone to 1.05 equiv of KH suspended in THF, followed by treatment with 1.25 equiv of BEt3 gives potassium enoxyborate 2a as a 90–95% regioisomerically pure species, as judged by its 1H and 13C NMR as well as by GLC analysis of the silylated products, while the use of KN(SiMe3)2 in place of KH gives 1a as a 90–95% pure substance. The KH-BEt3 procedure also gives 4 and 5 as 91 and 85% regiochemically pure species, respectively.

Metal-promoted cyclization: VI. Palladium-catalyzed cyclization via intramolecular allylation of alkenylmetals☆

Abstract Treatment of silyl-protected terminal alkynes containing an allylic alcohol moiety with Me3Al, i-Bu2AlH, ZnCl2, and a catalytic amount of Pd(PPh3)4, in this order, induces cyclization in cases where the reaction can lead to the formation of five-membered rings via either α- or γ-attack.

Butalactin: a new butanolide antibiotic from streptomyces corchorusii

Butalactin, (2R*,3S*)-2-(4′,5′-epoxy-hex-2′E-en)oyl-2-hydroxy-3-hydroxymethylbutanolide,(1) is a new antibiotic produced by a Streptomyces sp. HIL Y-86,36923. Butalactin is structurally related to the butyrolactones produced as signal molecules by microorganisms.