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Group: 2.0 alpha/beta
Submitted By: claggner (claggner)
Assigned to: Nobody/Anonymous (nobody)
Summary: SMARTS: chirality pattern "@?" not known
Patterns like "*[*@?](*)(*)*" (tetrahedral chiral
center and four single-bonded non-H substituents, with
specified or unspecified chirality) produce errors,
because "@?" can not be interpreted. See http://www.
html#RTFToC35 and http://www.daylight.com/dayhtml/doc/ theory/theory.smarts.html#RTFToC46 for documentation.
As I would understand it, this pattern should find
centers which are chiral, but where R/S is not set.
However, with this pattern Daylight's depictmatch
cgi) will also match CC(C)(C)C, which is not chiral at
all. So maybe I'm missinterpreting the use of this
pattern, but I guess that this is just an error in
depictmatch, because otherwise there would have been no
need to introduce "@?" at all, "**(*)(*)*" would also