Dichotomies in microwave-assisted propargyl-isomerization-Claisen domino sequences dependent on base strengths.

نویسندگان

  • Daniel M D'Souza
  • Wei-Wei Liao
  • Frank Rominger
  • Thomas J J Müller
چکیده

Microwave-assisted unimolecular isomerization-Claisen domino reactions of 1,3-di(hetero)aryl propargyl trityl ethers lead, depending on the basicity of the amine, either to the formation of tricyclo[3.2.1.0(2,7)]oct-3-enes (with triethylamine) or to indanes (with DBU). Based upon product analyses and computations, this base dependent dichotomy can be rationalized as a sequel of pericyclic reactions with intermediate protonation and deprotonation.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Coupling-isomerization-Claisen sequences - mechanistic dichotomies in hetero domino reactions.

A new coupling-isomerization-Claisen domino reaction starting from electron deficient halides and 1-(hetero)aryl propargyl trityl ethers dichotomizes in the concluding steps of the sequence and gives rise to the formation of tricyclo[3.2.1.0(2,7)]oct-3-enes, enones, 1H-isochromenes, or indans as a consequence of minute differences of substituent effects.

متن کامل

Microwave-assisted domino access to C2-chain functionalized furans from tertiary propargyl vinyl ethers.

Tertiary propargyl vinyl ethers armed with an electron-withdrawing group (amide or ester) at the tertiary propargylic position have been efficiently transformed into trisubstituted C(2)-chain functionalized furans. The metal-free domino transformation involves a microwave-assisted tandem [3,3]-propargyl Claisen rearrangement/5-exo-dig O-cyclization reaction. The manifold can be performed in a o...

متن کامل

FULL PAPER The Microwave-assisted Organocatalyzed Rearrangement of Pro- pargyl Vinyl Ethers to Salicylaldehyde Derivatives: A Combined Experimental and Theoretical Study

Herein we describe the microwave-assisted imidazolecatalyzed transformation of propargyl vinyl ethers (PVEs) into multisubstituted salicylaldehyde motives. The reaction is instrumentally simple, scalable and tolerates a diverse grade of substitution at the propargylic position of the staring PVE. The generated salicylaldehyde motives incorporate a broad range of topologies, spanning from simple...

متن کامل

Propargyl Claisen rearrangement: allene synthesis and beyond.

The propargyl Claisen rearrangement is a known protocol to gain access to functionalized allenes through the [3,3]-sigmatropic transformation of propargyl vinyl ethers. The correct use of appropriate propargyl vinyl ethers as starting materials coupled with suitable reaction conditions can aid in the development of new domino methodologies in which the allenes are valuable intermediates in rout...

متن کامل

Formal (3+3) cycloaddition of silyl enol ethers catalyzed by trifric imide: domino Michael addition-claisen condensation accompanied with isomerization of silyl enol ethers.

We describe here a Tf₂NH-catalyzed formal (3+3) cycloaddition of silyl enol ethers with acrylates as a new domino reaction. In the domino sequence, the catalyst activates Michael addition, deprotonation of the resulting silyloxonium cation and intramolecular Claisen condensation. It was found that reaction modes significantly depend on the reaction temperature. We also examined the mechanistic ...

متن کامل

ذخیره در منابع من

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Organic & biomolecular chemistry

دوره 6 3  شماره 

صفحات  -

تاریخ انتشار 2008