Neighboring Group Participation (NGP)
Assistance by an adjacent group forming bridged intermediates that alter stereochemical outcome.
Context: Can cause retention or special selectivity in substitutions.
Example: Participation by acetoxy in solvolysis.
Related Terms: SN1, SN2.
Reference: March, Advanced Organic Chemistry (2007).
Newman Projection
A perspective representation viewing along a C–C bond, useful for analyzing conformations.
Context: Widely used in stereo-electronic analysis and to visualize torsional strain.
Example: Staggered vs eclipsed ethane conformations.
Related Terms: Sawhorse Projection, Conformation.
Reference: Newman, JACS (1952).
NOE/NOESY
Nuclear Overhauser effect experiments probing through-space proximities.
Context: Establishes relative configuration and conformation.
Example: NOESY on cyclic diols.
Related Terms: J-Coupling, ROESY.
Reference: Claridge, High-Resolution NMR (2009).
Nonlinear Effects in Asymmetric Catalysis
Nonlinear relationship between catalyst ee and product ee due to catalyst aggregation or kinetics.
Context: Impacts process scale-up and control strategies.
Example: Kagan’s ML? model.
Related Terms: Kagan Model, Enantioselectivity.
Reference: Kagan & Blackmond, Acc. Chem. Res. (2000).
Noyori Hydrogenation
Asymmetric hydrogenation via bifunctional Ru/diamine catalysts.
Context: Industrial method for enantioenriched alcohols and amines.
Example: Hydrogenation of ketones with Ru-BINAP/diamine.
Related Terms: Asymmetric Catalysis, Transfer Hydrogenation.
Reference: Noyori, Angew. Chem. (1994/2001).