Salient features of the aza-Wacker cyclization reaction

Abstract

The intramolecular aza-Wacker reaction has unparalleled potential for the site-selective amination of olefins, but it is perhaps underappreciated relative to other alkene oxidations. The first part of this review makes...

Pd-Catalyzed N–H or C–H Functionalization/Oxidative Cyclization for the Efficient Synthesis of N-Aryl-Substituted [3,4]-Fused Pyrrolo­coumarins

“…A plausible mechanistic sequence for the transformation of 3-allyl-4-phenylaminocoumarin ( 3a ) into 2-methyl-1-phenylchromeno[4,3- b ]pyrrol-4(1 H )-one ( 6a ) is outlined in Scheme 2 , in analogy to aza-Wacker cyclization reaction presented in the literature. 17e 19a b e g i N-H activation, possibly, and coordination of palladium to the double bond results in the formation of palladated species A . Subsequent aminopalladation, through insertion of the double bond via a 5- exo - trig -cyclization, leads to the alkyl-Pd species B .…”

Tailored cobalt-salen complexes enable electrocatalytic intramolecular allylic C–H functionalizations

“…A noticeable drawback of the allyl-metal pathway is that its application to an internal alkene substrate usually produces a mixture of regioisomers, limiting most reactions to terminal alkenes 3 , 4 . The nucleometallation pathway, on the other hand, is compatible with internal alkenes and has been extensively studied since 1970s for the synthesis of N -heterocycles 5 – 9 . These intramolecular oxidative amination reactions, referred to as Aza-Wacker cyclizations, can be achieved under mild conditions using palladium catalysis with oxygen as the terminal oxidant, although the cyclization of densely substituted alkenes remains challenging 10 – 15 .…”

Hydroxyselenylation and Tethered Silanoxyselenylation of Allylic Silanols

“…"Tethering" a desired nucleophile to an existing functional group in the molecule of interest allows for intramolecular attack, which often proceeds with predictable regioselectivity and high diastereocontrol. [3][4][5][6][7][8][9][10] Our laboratory has provided the first examples of the use of silanol tethers for the intramolecular ring-opening of both transient and stable electrophiles. [11][12][13][14] Organoselenides have many attractive properties that make them complementary to organomercurials and organohalides.…”