γ-Lactone Synthesis via Palladium(II)-Catalyzed Lactonization of Unactivated Methylene C(sp3)–H Bonds

Abstract

A palladium(II)-catalyzed intramolecular lactonization of unactivated methylene C(sp 3 )-H bonds using PIP bidentate auxiliary is described. This method provides an efficient and concise pathway to synthesize functionalized γ-lactones.

Hypervalent iodine-mediated synthesis and late-stage functionalization of heterocycles

“…Liu and Shi have reported straightforward routes to access -lactones 93 via palladium (II)-catalyzed intramolecular dehydrogenative lactonization between carboxylic acids and γ-C(sp 3 )-H bond of substrates 92 using PhI(OAc)2 6 as the oxidant and (pyridin-2-yl)isopropyl amine (PIP) as the directing group (Scheme 22). 59 Among the various solvent and inorganic salts screened, toluene and NaI provided the best results. A variety of substituents on the alkyl chain of 92 were well tolerated.…”

Ring strain strategy for the control of regioselectivity. Gold-catalyzed anti-Markovnikov cycloisomerization initiated tandem reactions of alkynes

“…The skeleton of c-Lactone is found in a variety of bioactive natural products as a core structural element [16][17][18][19][20][21][22][23]. In addition, c-Lactones have also proven to be the vital precursors for the construction of many biologically active compounds and natural products [24][25][26][27][28][29][30].…”