165449-97-8Relevant academic research and scientific papers
NOVEL QUINOXALINE DERIVATIVES
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Page/Page column 188, (2008/06/13)
A quinoxalinone derivative of the formula (I): or a pharmaceutically acceptable salt or ester thereof, wherein; ???X is NH, S or the like; ???Y is O or the like; ???the partial structure is, for example, the formula: ???B1, B2, ....., Bn-1 and Bn, (in which n is 4 , 5 or 6) are each independently CH, N or the like; ???B'1, B'2, ....., B'n-1 and B'n (in which n is 4, 5 or 6) are each independently hydrogen or the like; and ???R is hydrogen, lower alkyl or the like.
Stereoselective Additions of Chiral, Functionalized Organozinc Reagents to Achiral and Chiral Aldehydes: a Matched-Mismatched Case in Organozinc Chemistry
Koert, Ulrich,Wagner, Holger,Pidun, Ulrich
, p. 1447 - 1458 (2007/10/02)
The additions of the enantiomerically pure organozinc reagents 17 and 33 to the THF-aldehyde 1 in the presence of the monodentate Lewis acid boron trifluoride-ether give the nonchelation-controlled addition products 7 and 36, respectively (stereoselectivity 95:5, 86:14).These results provide a route to oligo(tetrahydrofuran)s with the relative stereochemistry trans-syn-cis.A stereodirecting effect of the chiral center in the organozinc reagent 17 is found, leading to simple diastereoselectivies in the reaction with achiral aldehydes and to a matched-mismatched case in the reaction with the chiral aldehyde 1. - Key Words: Addition, stereoselective, nonchelation-controlled / Reagent, organozinc / Stereodifferentiation, double / Oligo(tetrahydrofuran)
