- Synthesis of acetylenic alcohols with calcium carbide as the acetylene source
-
Propargyl alcohols containing a terminal alkyne group are highly important and versatile intermediates. Here, we report the synthesis of these compounds from an inexpensive and renewable resource, calcium carbide (CaC2). No metal catalysts are required in this new protocol and the reactions take place under very mild conditions.
- Sum, Yin Ngai,Yu, Dingyi,Zhang, Yugen
-
supporting information
p. 2718 - 2721
(2013/10/08)
-
- Au-catalyzed formation of functionalized quinolines from 2-alkynyl arylazide derivatives
-
A new method for converting 2-alkynyl arylazide derivatives into functionalized polysubstituted quinolines following a gold-catalyzed 1,3-acetoxy shift/cyclization/1,2-group shift sequence has been developed. This transformation proceeds under mild reaction conditions, is efficient, and tolerates a large variety of functional groups.
- Gronnier, Colombe,Boissonnat, Guillaume,Gagosz, Fabien
-
p. 4234 - 4237
(2013/09/12)
-
- Evidence for the rapid conversion of stephacidin B into the electrophilic monomer avrainvillamide in cell culture
-
We report that the dimeric alkaloid stephacidin B (1) and the monomeric alkaloid avrainvillamide (2) function equivalently within experimental error to inhibit the growth of four different cultured human cancer cell lines. We also show that the proportion
- Wulff, Jeremy E.,Herzon, Seth B.,Siegrist, Romain,Myers, Andrew G.
-
p. 4898 - 4899
(2008/02/04)
-
- SYNTHESIS OF AVRAINVILLAMIDE, STEPHACIDIN B, AND ANALOGUES THEREOF
-
The syntheses of the natural products, avrainvillamide and stephacidin B, are provided. The α,β-unsaturated nitrone functionality of avrainvillamide and its 3- alkylidene-3H-indole 1 -oxide core is shown to covalently and reversibly bond to heteroatom-based nucleophiles. This capability may allow these molecules to bind active site nucleophiles and may provide the basis for designing potent and selective enayme inhibitors. Both avrainvillamide and its dimer stephacidin B have been reported to exhibit antiproliferative activity, and avrainvillamide has been reported to exhibit antimicrobial activity against multi-drug resistant bacteria. Avrainvillamide has been found to target cytoskeleton-linking membrane protein (CLIMP-63) thereby preventing cells from undergoing mitosis. The invention provides syntheses of these natural products as well as analogs of these natural products and their functional cores. The compounds of the invention may be used in the treatment of diseases such as cancer, autoimmune diseases, and bacterial infection.
- -
-
Page/Page column 31/33
(2008/06/13)
-
- PtCl2-mediated cycloisomerization of unsaturated propargylic carboxylates
-
The PtCl2-mediated cycloisomerization of unsaturated propargylic carboxylates yields differently functionalized bicyclo[4.1.0]heptane enol esters from moderate to good yield, in a very diastereoselective manner. We have prepared and submitted to PtCl2-catalyzed cycloisomerization a series of differently substituted hept-1-en-6-ynes with different O-acyl (acetyl, trichloroacetyl, 3,4,5-trimethoxybenzoyl, etc.) protecting groups at propargylic positions, investigating also the effect of the geometry at the double bond, as well as the effect of the number of substituents at the alkene moiety. As a result, we have found that the O-acetyl migrating group is the best one in terms of simplicity and chemical yields. In this reaction we have isolated mixtures of compounds formed by minor 1-acetoxy-allenes and major bicyclo[4.1.0]heptane derivatives. Major products are the result of a sequential process involving steps of cycloisomerization plus cyclopropanation, followed by acyl migration. The basic methanolysis (K2CO3, MeOH) of these intermediates gave mixtures of cis and trans-caran-2-ones. This two-step protocol (cycloisomerization plus basic methanolysis) for the syntheses of α,β-unsaturated cyclopropyl ketones constitutes a synthetic alternative to the usual unfriendly, intramolecular cyclopropanation of unsaturated α-diazocarbonyl derivatives. The formation of these bicyclo[4.1.0]heptane derivatives is a simple, but efficient entry into the skeleton of the 'carane' family of natural products.
- Anjum, Shazia,Marco-Contelles, José
-
p. 4793 - 4803
(2007/10/03)
-