3638-64-0Relevant articles and documents
Organocatalytic Enantioselective Michael-Aldol[3+2] Annulation for the Synthesis of Nitro-Methanobenzo[7] annulenes
Liu, Jin-Yu,Zhang, Xiao-Hai,Zhang, Yang
supporting information, p. 5008 - 5011 (2021/09/28)
We report an enantioselective Michael-Aldol[3+2] annulation between 2-alkyl-3-hydroxynaphthalene-1,4-diones and nitroalkenes using a bifunctional thiourea catalyst, and a series of nitro-methanobenzo[7]annulenes with potential biological activities were synthesized in good yields with excellent enantio- and diastereoselectivities. A gram-scale synthesis and further transformation of the product demonstrated the synthetic value of this reaction.
Enantioselective catalytic approach to the C23–C28 subunit of 24α-methyl steroids
Yakimchyk, Viktoryia S.,Kazlova, Volha V.,Hurski, Alaksiej L.,Savchenko, Rimma G.,Kostyleva, Svetlana A.,Zhabinskii, Vladimir N.,Khripach, Vladimir A.
supporting information, p. 82 - 90 (2019/05/24)
Enantioselective synthesis of C23–C28 subunit of campestane steroids based on catalytic methods is reported. The synthesis was started from (S)-2-isopropyl-4-nitrobutan-1-ol, which is easily accessible by the reaction between isovaleraldehyde and nitroethylene catalyzed by only 2% of (S)-trimethylsilyldiphenylprolinol. Removal of one “extra” carbon from the nitroalcohol was achieved by Ni-catalyzed hydrodecarboxylation of the redox-active ester intermediate. The synthesized C23–C28 fragment was attached to a steroidal core by Julia-Kocienski reaction of a steroidal aldehyde with metallated C23–C28 sulfone. The obtained product of olefination was easily transformed to a precursor of campesterol and (Z)-22-dehydrocampesterol.
Zeolite Y-assisted nitration of aromatic and heterocyclic compounds and decarboxylative nitration of α,β-unsaturated acids under non-conventional conditions
Sudhakar Chary,Rajanna,Krishnaiah,Srinivas
, p. 1430 - 1434 (2016/03/08)
Zeolite Y was found to be an efficient catalyst for a facile nitration of aromatic compounds with acetonitrile as the solvent in the presence of small amounts of HNO3 at room temperature. The reactions afforded mono-nitro derivatives of aromatic compounds in about three hours under stirred conditions with high yields and regioselectivity. The reaction times drastically reduced to about 20 min under sonication and to about 20 s under microwave irradiation. Zeolite is recovered after completion of the reaction and recycled for three to four times without any problem. The approach is particularly appropriate for the conversion of unsaturated cinnamic acids into nitrostyrenes.