The aldol-type condensation of methyl diazoacetate with 3-organyl-silyl and -germyl propynals and their carbon analogues

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

“…Methods were developed for the synthesis of polyfunctionalized pyrazoles by the reactions of various acetylene compounds with diazo compounds [264][265][266][267] Low-temperature reactions of isothiocyanates with lithium and potassium amides were discovered and studied systematically, and a fundamentally new strategy for the one-pot assembly of pyrroles [99,102,[171][172][173], thiazoles [99,[273][274][275][276][277][278], and imidazoles [277][278][279][280][281] was developed from them. SR 1 R 1 S By using a mixture of heterocumulenes it is possible to achieve the controlled cascade assembly of polyfunctionalized thiazoles [99,277].…”

Esters of 4-formylpyrazol-3-carboxylic acids

“…При дослідженні регіоселективності циклопри-єднання метилового естеру діазооцтової кисло-ти 4 до 3-фенілпропіналю 5 [2] встановлено, що в діетиловому етері при кімнатній температурі такий процес супроводжується утворенням трьох продуктів -ізомерних формілестерів 6 і 7 та нецик-лічного метилового естеру 5-феніл-3-гідрокси-2-діазопропін-4-ової кислоти 8 (схема 2).…”

“…Трикомпонентна конденсація 1-заміщених есте-рів 4-формілпіразол-3-карбонових кислот 21 із ацетооцтовим естером та його єнаміном у спів-відношенні 1 : 1 : 1 у присутності іонних рідин R = 4-ClC 6 H 4 , (Me) 2 приводить до утворення ансамблів із піразоль-ного та 1,4-дигідропіридинового циклу 92 [9] (схема 41). Сполуки 92 [40] також були отримані при ви-користанні ацетооцтового естеру і ацетату амо-нію (схема 42).…”

Silicon- and germanium-substituted propynals as ambident electrophiles for the design of new heterocycles and polyfunctional acetylenes

“…148-150 The presence of Si or Ge containing substituents in position 4 of the pyrazole ring facilitates their dimerization into tricyclic hemiaminals 28a,b,d, which can be explained by the π withdrawing effect of the R 3 Si or R 3 Ge groups in 5 formylpyrazoles 27a,b,d, increasing electrophilicity of the C atom of the carbonyl group and lability of the NH protons. 26 We investigated the reaction of propynal 2a and unsubstituted propynal 2i with Me 3 SiN 3 in order to study effects of their structure on regioselectivity of addition, as well as on ability of 5 formyl substituted 1,2,3 triazoles to dimerize into the corresponding cyclic bis(hemi aminals). There is no information on dimerization of 1H 1,2,3 triazole 5 carboxaldehydes in the literature.…”

“…15 Synthetic potential of substituted propynals and their element containing analogs also includes efficient methods for the synthesis of chiral homoallylic amines and amino acids, 16 propargylamines as precursors of azomethine ylides, 17 dithianes, 18 diazepines, 19 1,3 enynes by the Horner-Emmons reaction, 20 α,β unsaturated esters (as a result of the carbene induced stereoselective esterifica tion of alkynylaldehydes), 21 epoxy diynes, the key frag ments of neocarcinostatine (highly efficient antibacterial and antitumor agent 22 ), hydroxy containing triynes, 23 car bonyl containing enynes, which cyclize into α vinyl furans. 24 The use of trimethylsilylpropynal as a dipolaro phile allows one to obtain functionalized pyrazoles 25, 26 and triazoles. 27, 28 The interest of researchers to the chemistry of propynals is stimulated to a great extent by the fact that some of them were isolated from plants, 29 they participate in biоchemical processes and have high biological activity.…”