SN1-Type Reactions in the Presence of Water: Indium(III)-Promoted Highly Enantioselective Organocatalytic Propargylation of Aldehydes
作者:Riccardo Sinisi、Maria Victoria Vita、Andrea Gualandi、Enrico Emer、Pier Giorgio Cozzi
DOI:10.1002/chem.201100729
日期:2011.6.27
Water under troubled chemistry! The first catalytic stereoselective addition of aldehydes to internal functionalized propargylic alcohols promoted by a combination of organocatalysis and indium triflate is described (see scheme). The reaction is tolerant of functional groups (FG) and was performed in the presence of water. High enantioselectivities (anti, 92–99 % ee) and moderate diastereomeric ratios
The first Lewisacid catalyzed stereoconvergent transformation of racemic 2-(hetero)aryl- N-sulfonylaziridines via C-N bond cleavage with nucleophiles is presented. This includes the [3 + 2] annulations with (hetero)aromatic aldehydes and 1,3-disubstituted indoles, asymmetric Friedel-Crafts type reaction with electron-rich (hetero)arenes, and asymmetric aminolysis with amines, providing facile access
FuligocandinB (2) is a novel natural product that can overcome TRAILresistance. We synthesized enatiomerically pure fuligocandinB (2) and its derivative 5′‐I fuligocandinB (4), and found that the latter had an improved biological activity against the human gastric cancercell line, AGS. We attached a biotin linker and photoactivatable aryl diazirine group to 5′‐I fuligocandinB (4), and employed
Direct C-3 lithiation of 1-(triisopropylsilyl)indole
作者:Mai Matsuzono、Tsutomu Fukuda、Masatomo Iwao
DOI:10.1016/s0040-4039(01)01656-2
日期:2001.10
1-(Triisopropylsilyl)indole can be directly lithiated at 3-position with tort-BuLi-TMEDA in hexane at 0 degreesC for 3 h. The generated lithio species is reacted with a variety of electrophiles to give 3-substituted 1-(triisopropylsilyl)indoles in good yields. (C) 2001 Elsevier Science Ltd. All rights reserved.