报道了从唑醛制备取代的N-稠合芳香杂环的有效途径,包括中氮茚、咪唑并[1,2- a ]吡啶和咪唑并[1,5- a ]吡啶。醛与富马腈和三乙基膦的维蒂希烯化主要提供E-烯烃,其在用弱碱处理后经历快速环化。显示了所得杂芳族双环的 1-、2-和 3-位的取代基控制。或者,可分离的E-烯烃用亲电子试剂进行选择性烷基化,然后原位环化成在6-位额外取代的中氮茚。
One-Pot Synthesis of Highly Substituted <i>N</i>-Fused Heteroaromatic Bicycles from Azole Aldehydes
作者:Victor K. Outlaw、Felipe B. d’Andrea、Craig A. Townsend
DOI:10.1021/ol5036936
日期:2015.4.17
An efficient route to substituted N-fused aromaticheterocycles, including indolizines, imidazo[1,2-a]pyridines, and imidazo[1,5-a]pyridines from azole aldehydes, is reported. Wittig olefination of the aldehydes with fumaronitrile and triethylphosphine affords predominantly E-alkenes that undergo rapid cyclization upon treatment with a mild base. Substituent control of the 1-, 2-, and 3-positions of
报道了从唑醛制备取代的N-稠合芳香杂环的有效途径,包括中氮茚、咪唑并[1,2- a ]吡啶和咪唑并[1,5- a ]吡啶。醛与富马腈和三乙基膦的维蒂希烯化主要提供E-烯烃,其在用弱碱处理后经历快速环化。显示了所得杂芳族双环的 1-、2-和 3-位的取代基控制。或者,可分离的E-烯烃用亲电子试剂进行选择性烷基化,然后原位环化成在6-位额外取代的中氮茚。
Lithiation of the 6-dimethylamino-1-azafulvene dimer. A versatile synthesis of 5-substituted pyrrole-2 carboxaldehydes.
作者:Joseph M. Muchowski、Petr Hess
DOI:10.1016/s0040-4039(00)80207-5
日期:1988.1
Metalation of the dimer of 6-dimethylamino-1-azafulvene, with t-butyllithium at −15°C, gave the 3,8-dilithio derivative , which after reaction with diverse electrophilic reagents and hydrolysis, provided a wide variety of 5-substituted pyrrole-2-carboxaldehydes .
Total Synthesis of (±)-Rhazinal Using Novel Palladium-Catalyzed Cyclizations
作者:Alfred L. Bowie、Dirk Trauner
DOI:10.1021/jo801791j
日期:2009.2.20
A concise synthesis of (±)-rhazinal that hinges on novel oxidative Heck cyclizations and palladium-catalyzed direct couplings is described. An X-ray structure of N-MOM-rhazinal, which provides insight into the conformation of the strained 9-membered lactam ring, is described.
The rare chemoselectivity between two different aryl halides was realized by optimizing the kinetics of the different steps of this multicomponent process. The new developed method led to the rapidsynthesis of rhazinal in a highly efficient manner.
New group 14 5-metallated pyrrole-2-carbaldehydes 5-R3E(C4H2NR′)CHO (E Si, Ge, Sn; R Me, Et, nBu; R′ H, Me) have been regiospecifically prepared from corresponding pyrrole-2-carbaldehydes by either (i) 5-lithiation after protection of the aldehyde function by treatment with lithium N-methylpiperazide or by formation of an azafulvene dimer or (ii) metallation by R3EX (X Cl, Br). The 5-silylated