Synthesis of a Bicyclo[8.3.1]enediyne via Chromium-Mediated Dearomatization of 2,6-Bis(trimethylsilyl)anisole

Abstract

S y n t h e s i s o f a B i c y c l o [ 8 . 3 . 1 ] e n e d i y n e v i a C h r o m i u m -M e d i a t e d D e a r o m a t i z a t i o n

Intramolecular Nicholas Reactions in the Synthesis of Heteroenediynes Fused to Indole, Triazole, and Isocoumarin

“…Electrophile-promoted cyclization , and CuAAC of 1-iodoacetylenes , being applied to diacetylenes , with subsequent Sonogashira coupling , have been suggested as key steps for the construction of acyclic enediyne systems. The Nicholas reaction was chosen for the final macrocyclization step as a unique synthetic tool for the construction of various cyclic alkyne derivatives including natural enediynes and their analogues. − …”

6-Exo-dig cyclization/dearomatization cascade towards N–O fused spiro polyheterocycles

“…[25][26][27][28][29] However, the studies on dearomatization reactions of anisoles to construct valuable spirocyclohexadienone structures, are very limited due to low reactivity. [30][31][32] Meanwhile, a protocol based on dearomatization for the efficient construction of structurally novel N-O fused spiro polyheterocycles has rarely been explored. [33][34][35] As a result of the significance of metal-free approaches in academia and industry, as well as our continuing interest in the preparation of novel polyheterocycles, [36][37][38][39][40] we herein develop a metal-free tandem cyclization of N-alkoxybenzamides for the synthesis of diverse N-O fused spiro polyheterocycles by employing a hypervalent iodine(III) reagent (Scheme 1c).…”