Nano-copper catalysed highly regioselective synthesis of 2,4-disubstituted pyrroles from terminal alkynes and isocyanides
作者:Dipak Kumar Tiwari、Jaya Pogula、B. Sridhar、Dharmendra Kumar Tiwari、Pravin R. Likhar
DOI:10.1039/c5cc04166j
日期:——
Nano-copper(0) stabilized on alumina prepared from Cu–Al hydrotalcite has been reported for completely regioselective synthesis of 2,4-disubstituted pyrroles from unactivated terminal aromatic/aliphatic alkynes and isocyanides.
Silver acetate catalysed cycloadditions of isocyanoacetates
作者:Ronald Grigg、Mark I. Lansdell、Mark Thornton-Pett
DOI:10.1016/s0040-4020(98)01216-2
日期:1999.2
Silveracetate is an efficient catalyst for the cycloaddition of methyl isocyanoacetate with Michael-acceptors under mild conditions to give Δ1- or Δ2-pyrrolines in good yields. In the case of acrolein, novel chemoselectivity was observed. In the absence of a suitable olefin isocyanoacetates undergo silveracetate catalysed cyclodimerisation to give imidazoles in excellent yields. The mechanism of
The alkylation of imidazole-4(5)-carboxylic acid anilide and methyl ester with bromoacetic acid and its methyl ester in neutral and alkaline media yields, along with monoalkylation products, 1,3-bis(2-methoxycarbonylmethyl)-4-R-imidazolium bromide. The monoalkylation of methyl imidazole-4(5)-carboxylate yields a I :1 mixture of the 1,4- and 1,5-isomers, and the monoalkylation of imidazole-4(5)-carboxylic anilide selectively provides the 1,4-isomer.
Versatile Direct Synthesis of Oligosubstituted Pyrroles by Cycloaddition of α-Metalated Isocyanides to Acetylenes
作者:Oleg V. Larionov、Armin de Meijere
DOI:10.1002/anie.200502140
日期:2005.9.5
A general and practical route to 4,5-disubstituted oxazoles using acid chlorides and isocyanides
An efficient and mild method for the synthesis of 4,5-disubstituted oxazoles has been developed. A series of 4,5-disubstituted oxazoles were prepared via [3 + 2] cycloaddition reaction of various isocyanides and acid chlorides in the presence of base. This method serves as an efficient preparation of 5-formyloxazole which might prove to be a synthetically useful intermediate.