18729-46-9Relevant articles and documents
A Vinyl Cyclopropane Ring Expansion and Iridium-Catalyzed Hydrogen Borrowing Cascade
Cheong, Choon Boon,Christensen, Kirsten E.,Donohoe, Timothy J.,Frost, James R.,Wübbolt, Simon
supporting information, p. 11339 - 11344 (2020/05/25)
A vinyl cyclopropane rearrangement embedded in an iridium-catalyzed hydrogen borrowing reaction enabled the formation of substituted stereo-defined cyclopentanes from Ph* methyl ketone and cyclopropyl alcohols. Mechanistic studies provide evidence for the ring-expansion reaction being the result of a cascade based on oxidation of the cyclopropyl alcohols, followed by aldol condensation with the pentamethyl phenyl-substituted ketone to form an enone containing the vinyl cyclopropane. Subsequent single electron transfer (SET) to this system initiates a rearrangement, and the catalytic cycle is completed by reduction of the new enone. This process allows for the efficient formation of diversely substituted cyclopentanes as well as the construction of complex bicyclic carbon skeletons containing up to four contiguous stereocentres, all with high diastereoselectivity.
4,6-SUBSTITUTED-PYRAZOLO[1,5-a]PYRAZINES AS JANUS KINASE INHIBITORS
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Paragraph 00357, (2016/06/28)
Compounds of Formula I: and stereoisomers and pharmaceutically acceptable salts and solvates thereof in which R1, R2, R3 and R4 have the meanings given in the specification, are inhibitors of one or more JAK kinases and are useful in the treatment of JAK kinase-associated diseases and disorders, such as autoimmune diseases, inflammatory diseases, rejection of transplanted organs, tissues and cells, as well as hematologic disorders and malignancies and their co-morbidities.
A facile entry to secondary cyclopropylcarbinols: Further developments in the stereospecific synthesis of (E)-homoallylic bromides
Ferreri,Ambrosone,Chatgilialoglu
, p. 3351 - 3356 (2007/10/03)
Cyclopropanecarboxaldehyde has been used in an improved synthesis of secondary cyclopropylcarbinols, thus allowing for further developments in the stereospecific ring opening leading to (E)-homoallylic bromides.
SIMPLE SYNTHESIS OF ACETOGENIN TRANSOID INSECT PHEROMONES STARTING FROM ACETYLCYCLOPROPANE
Cheskis, B. A.,Ivanova, N. M.,Moiseenkov, A. M.,Nefedov, O. M.
, p. 1372 - 1380 (2007/10/02)
A highly effective synthesis of a series of alkyl and 1-alkenyl cyclopropyl ketones, which are key components in the complete synthesis of a large number of transoid lepidoptera pheromones, has been developed, based on the alkylation of N-cyclohexyl-1-cyclopropylethylideneimine or its condensation with aldehydes.
Acetylcyclopropane as a Five-Carbon Building Block in the Synthesis of some Acetogenin Insect Pheromones
Moiseenkov, Alexander M.,Czeskis, Boris A.,Ivanova, Natalya M.,Nefedov, Oleg M.
, p. 2639 - 2649 (2007/10/02)
Interaction of deprotonated acetylcyclopropane cyclohexylimine with several aliphatic alkyl halides, epoxides, and aldehydes efficiently gave the corresponding cyclopropyl ketones.Some of the respectible alcohols were rearranged in a highly stereoselective manner under the action of trimethylsilyl bromide in the presence of zinc bromide into the corresponding linear (E)-homoallyl bromides.The latter were used, in turn, as key intermediates in concise syntheses of thirteen terminally functionalized straight-chain oligoolefins which are known to constitute acetogenin pheromonal components for more than 65 species of lepidopteran insects.
SYNTHESIS OR FORMYLCYCLOPROPANE, ALKYL CYCLOPROPYL KETONES, AND CYCLOPROPYLCARBINOLS ON THE BASIS OF γ-ELIMINATION UNDER THE CONDITIONS OF PHASE-TRANSFER CATALYSIS
Khusid, A. Kh.
, p. 112 - 115 (2007/10/02)
A preparative method was developed for the synthesis of formylcyclopropane and alkyl cyclopropyl ketones on the basis of the method proposed for the production of 4-chlorobutanal and alkyl 3-chloropropyl ketones.With ethylmagnesium bromide formylcyclopropane gives a high yield of 1-cyclopropyl-1-propanol.
Regioselective Route to Sterically Hindered Cyclopropylcarbinyl Halides
Hrubiec, Robert T.,Smith, Michael B.
, p. 431 - 435 (2007/10/02)
Reaction of cyclopropylcarbinyl alcohols 1 with hexachloroacetone and triphenylphosphine resulted in 80 - 90 percent yields of the corresponding cyclopropylcarbinyl chlorides 4 regioselectively, with no trace of the homoallylic chloride 2 or the chlorocyclobutane derivative 6a.Similar reaction of 1 with bromine and triphenylphosphine, in dimethylformamide, gave 65 - 80 percent yields of the cyclopropylcarbinyl bromide 5 with trace amounts of the homoallylic bromide 3 but no detectable bromocyclobutane derivative 6b.These reactions are amenable to the preparation of very sterically hindered cyclopropylcarbonyl halides, heretofore inaccessible, regioselectively and in a facile manner.
