6366-30-9Relevant academic research and scientific papers
Chiral cyclopentadienyl RhIII-catalyzed enantioselective cyclopropanation of electron-deficient olefins enable rapid access to UPF-648 and oxylipin natural products
Duchemin, Coralie,Cramer, Nicolai
, p. 2773 - 2777 (2019/03/05)
Chiral cyclopentadienyl RhIII complexes efficiently catalyze enantioselective cyclopropanations of electron-deficient olefins with N-enoxysuccinimides as the C1 unit. Excellent asymmetric inductions and high diastereoselectivities can be obtained for a wide range of substrate combinations. The reaction proceeds under mild conditions without precautions to exclude air and water. Moreover, the synthetic utility of the developed method is demonstrated by concise syntheses of members of the oxylipin natural products family and the KMO inhibitor UPF-648.
Systematic investigations on the reduction of 4-aryl-4-oxoesters to 1-aryl-1,4-butanediols with methanolic sodium borohydride
Chaudhuri, Subrata Kumar,Saha, Manabendra,Saha, Amit,Bhar, Sanjay
supporting information; experimental part, p. 748 - 755 (2011/01/03)
4-Aryl-4-oxoesters undergo facile reduction of both the keto and the ester groups with methanolic NaBH4 at room temperature to yield the corresponding 1-aryl-1,4-butanediols whereas 4-alkyl-4-oxoesters furnish the corresponding 1,4-butanolides via selective reduction of the keto moiety. Results of a detailed and systematic investigation of the reaction are described.
Preparation of aryl-substituted E-homoallylic bromides from cyclopropylcarbinol and PBr3
Roy, Sanchita,Guha, Sharmistha,Kumar Dutta, Samit,Bhar, Sanjay
, p. 1919 - 1922 (2007/10/03)
An expeditious synthesis of aryl substituted E-homoallylic bromides has been accomplished by the cleavage of cyclopropylcarbinols with phosphorus tribromide. Copyright Taylor & Francis Group, LLC.
Photochemical synthesis of highly functionalized cyclopropyl ketones
Wessig, Pablo,Muehling, Olaf
, p. 865 - 893 (2007/10/03)
A series of di- and trisubstituted cyclopropyl ketones 11 were prepared by irradiation of ketones 3 and 5, which bear a leaving group adjacent to the carbonyl C-atom. The required ketones 3 could be easily synthesized either by functionalization of ketones 1 with a hypervalent iodine reagent, 2, or by O-sulfonylation of α-hydroxy ketones 7. The nitrates 5 were obtained by treatment of the corresponding α-bromo ketones with AgNO3. The irradiation of 3 and 5 must be performed in the presence of an acid scavenger (1-methyl-1H-imidazole) to obtain the cyclopropanes 11 in good yields. The synthetic efficiency of the method was, among other things, demonstrated by the preparation of a highly strained bicyclo[2.1.0]pentane 11i in good yield. The mechanism of the photochemical cyclization was investigated by means of photokinetic measurements, as well as by quantum-chemical calculations. It was shown that the presence of the leaving group substantially influences all steps of the photochemical reaction cascade. The X-ray crystal structures of 11j and exo-11k were also determined.
A new photochemical route to cyclopropanes
Wessig, Pablo,Muehling, Olaf
, p. 1064 - 1065 (2007/10/03)
Especially highly substituted cyclopropanes can be produced with a new photochemical approach. Starting with aromatic ketones that bear a leaving group adjacent to the carbonyl carbon atom, photolysis leads to the formation of 1,3-diradicals, which efficiently cyclize to cyclopropanes (see scheme; Ms=MeSO2).
