Novel and efficient synthesis of pyrroloiminoquinones using a hypervalent iodine(III) reagent

Hypervalent Iodine(III)‐Mediated Cascade Cyclization of Propargylguanidines and Total Syntheses of Kealiinine B and C

“…The groups of Kita,–,, and Domínguez,, have performed a broad investigation of the utility of the hypervalent iodine reagents phenyliodonium diacetate (PIDA) and phenyliodonium ditrifluoroacetate (PIFA) with regards to their utility for oxidative cyclization reactions. In 2011, Canesi et al designed a cascade cyclization mediated by PIDA for the synthesis of ring‐fused skeletons .…”

Development of Novel Reactions Using Hypervalent Iodine(III) Reagents: Total Synthesis of Sulfur-Containing Pyrroloiminoquinone Marine Product, (±)-Makaluvamine F

“…31 We have developed a facile and direct preparation of quinone imine derivatives, 12,21,22,27a and very recently we have communicated the synthesis of pyrroloiminoquinones from the indole bearing an alkyl azido sidechain. 32 The starting substrate was prepared as follows (Scheme 3). The treatment of 6,7-dimethoxyindole (5) 33 with oxalyl chloride followed by LAH reduction gave 3-(hydroxyethyl)indole (6) (95% yield) which was converted to 3-(azidoethyl)indole (8) via 3-(iodoethyl)indole (7) in 65% yield.…”

Synthetic Studies on the Sulfur-Cross-Linked Core of Antitumor Marine Alkaloid, Discorhabdins: Total Synthesis of Discorhabdin A

“…Tritylation of 5 followed by monobromination with NBS yielded 10 in 65 % yield (2 steps; Scheme ). A coupling reaction of 10 with pyrroloiminoquinone 11 a , which was prepared by our previously developed PIFA‐induced pyrroloiminoquinone formation,9 provided 12 in 46 % yield. We then examined the oxidative spirocyclization reaction of 12 using PIFA.…”