Selective Ketone Pyrolysis: New Synthetic Method for Mono‐ and Polycyclic Hydrocarbons

Abstract

Ring formation with p‐toluenesulfonylmethyl isocyanide (TosMIC), and successive CO loss, leads preparatively to hitherto unobtainable or not easily obtained polycyclic hydrocarbons. From the triketone 1, the ketone intermediates 2 and 3 and the hydrocarbon 4 can be isolated.

Synthesis and conformational studies of 9-substituted [3.3]metacyclophane-2,11-diones and conversion to the corresponding [3.3]metacyclophanes

“…Vögtle reported [14][15][16][17] the preparation of carbocyclic [3 n ]MCPs using TosMIC 18,19 as the cyclisation reagent, which was applied in a new cyclisation procedure without phase-transfer conditions. [20][21][22][23][24] This strategy can be employed for the preparation of [3.3]MCP containing two benzene rings.…”

“…We have improved the addition procedure in Vögtle' method. [14][15][16][17] Thus, to a suspension of NaH in DMF a solution of 3 and TosMIC adducts 2 was added dropwise in DMF at room temperature. This not only improves the yield of the desired ketones but also makes the handling of the base (solid NaH) easier.…”

High Quality Biowaxes from Fatty Acids and Fatty Esters: Catalyst and Reaction Mechanism for Accompanying Reactions

“…A similar behavior has been reported for cyclic ketones, which achieve ring contraction by carbon monoxide removal. 49,50 Unlike the cyclic derivatives, the alkyl chains do not recombine, but they undergo further free radical chain reactions. Under these conditions, also the formation of unlabeled methane can be assumed.…”

Cation templated improved synthesis of pillar[6]arenes

“…16 Templated synthesis is a common strategy to steer product selectivity in a chemical reaction towards a particular molecule exploiting its recognition properties towards the templating unit. Examples of this strategy are the synthesis of crown ethers 17 or catenanes 18 based on metal ion chelates, cyclotrimers 19 with a porous coordination framework, paracyclophanes 20 with covalently bond template as well as materials like mesoporous silica MCM-41 using surfactants. 21 In the present contribution we report an improved synthesis of P [6] carried out with the templating approach based on the right selection of cationic guests characterized by proper size Scheme 1 Synthesis of P [5] and P [6] with FeCl 3 as catalyst in the presence of different cationic templating units T1-T4.…”