89634-38-8Relevant academic research and scientific papers
Chiral N-heterocyclic carbene-iridium complexes for asymmetric reduction of prochiral ketimines
Kathuria, Lakshay,Samuelson, Ashoka G.
, (2020/12/28)
Enantioselective reduction of imines to the corresponding chiral secondary amines has been studied using a series of chiral half-sandwich iridium complexes. Chiral N-heterocyclic carbene (NHC) ligands in these complexes were synthesized from readily available, naturally occurring amino acids. Inexpensive phenylsilane was used as a convenient hydrogen donor. Under the optimized conditions, Ir-NHC complexes could reduce ketimines in good yields, albeit with moderate enantiomeric excess (ee). The phenylglycine derived chiral NHC was shown to give the best Ir catalyst and it also gave the maximum ee compared to catalysts prepared from other NHCs in this series. The opposite enantiomer of the reduction product was always obtained while using the Ir complex bearing a valine based NHC. The yields were consistently high with a variety of imine substrates having different steric and electronic demands.
Antitumoral compounds
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, (2008/06/13)
New spisulosine derivatives of use in treating tumors are of the formula (I) wherein: each X is the same or different, and represents H, OH, OR′, SH, SR′, SOR′, SO2R′, NO2, NH2, NHR′, N(R′)2, CN, halogen, C(=O)H, C(=O)CH3, CO2H, CO2CH3, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaromatic, or two groups X may together form =O; Y is NR1, OR1, PR1, SR1, or halogen, wherein the number of substituents R1 is selected to suit the valency and each R1 is independently selected of H, OH, C(=O)R′, P(=O)R′R″, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted aryl, and wherein the dotted line indicates an optional double bond; each Z is the same different, and represents H, OH, OR′, SH, SR′, SOR′, SO2R′, NO2, NH2, NHR′, N(R′)2, NHC(O)R′, CN, halogen, C(=O)H, C(=O)CH3, CO2H, CO2CH3, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaromatic, or two groups Z may together form =O; z is 0 to 25; y is to 0 to 20; R2 is H, C(=O)R′, P(=O)R′R″, S(=O)R′R″, S(=O)2R′, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 Alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted aryl; R3 is H, C(=O)R′, P(=O)R′R″, S(=O)R′R″, S(=O)2R′, substituted or unsubstituted C1-C18 alklyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted aryl; each of the R′, R″ groups is independently selected from the group consisting of H, OH, NO2, NH2, SH, CN, halogen, =O, C(=O)H, C(=O)CH3, CO2H, CO2CH3, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynl, substituted or unsubstituted aryl; there may be one or more unsaturations in the hydrocarbon backbone defined by the chain (II) and salts thereof; with the exception of a C16-C24 2-amino-3-hydroxyalkane or a C16-C24 2-amino-3-hydroxyalkene.
PREFERRED GAUCHE CONFORMATION IN N-(2-AMINOETHYL)PYRIDINIUM IONS
Razenberg, Johannes A. S. J.,Nolte, Roeland J. M.,Drenth, Wiendelt,Kanters, Jan A.,Duijneveldt, Frans B. van
, p. 111 - 118 (2007/10/02)
X-ray analysis of 1-pyridinium p-toluenesulphonate and 1-pyridinium p-toluenesulphonate reveals that in both compounds the central N-C-C-N moiety is in the syn-clinal confor
