Hypervalent iodine mediated radical cyclization of o-(allyloxy)arylaldehydes and N-hydroxyphthalimide (NHPI) under metal-free conditions

Updates on hypervalent-iodine reagents: metal-free functionalisation of alkenes, alkynes and heterocycles

“…Mechanistic investigations revealed that the transformation proceeds via a radical pathway (Scheme 54). 110…”

“…Mechanistic investigations revealed that the transformation proceeds via a radical pathway (Scheme 54). 110 Strained small-ring heterocycles are of significant importance in drug molecules as well as bioactive natural products, and they are also useful intermediates in organic synthesis. 111…”

“…131 In 2017, the Li group reported a site-selective oxidative C-H sulfonylation method for 8-acylaminoquinolines (109) and anilides using sulfonyl chlorides and PhI (OPiv) 2 . C5-Sulfonylated quinolines (110) were obtained with good functional group compatibility and high tolerance to air and moisture (Scheme 72). 132 Pyrrolo [2,3-d]pyrimidines closely resemble biogenic purine bases with diverse biological activities.…”

Recent advances in free radical cyclizations of 2-alkenyl benzaldehydes to synthesize benzocycloketones

“…of PhI(OAc) 2 as the oxidant. 42 In the absence of transition metals, some valuable functionalized chroman-4-ones were efficiently synthesized (Scheme 25).…”

Synthesis of N-alkoxyphthalimide derivatives via PIDA-promoted cross dehydrogenative coupling reaction

“… 15 Recently, a PIDA-mediated radical cyclization of o -(allyloxy)arylaldehydes with NHPI has been realized by Wang's group. 16 At the outset of this investigation, we chose 1,2-diphenylethanone 1a and N -hydroxyphthalimide 2a as the model substrates to optimize the reaction conditions ( Table 1 ). The reaction went smoothly and the desired product 3a could be obtained in 92% yield by using PIDA as the oxidant and dichloromethane as a solvent at room temperature under air atmosphere ( Table 1 , entry 1).…”