Felkin-Ahn Model Flashcards
1
Q
characteristics of a-stereogenic carbonyls
A
free rotation about C-C bond, under kinetic control, Nu attacks anti to largest substituent and 107 to C=O
if have electronegative substituent class as largest group
2
Q
Why does electronegative group count as large?
A
electronegative atom placed at 90 to CO giving low energy s* AO, overlaps well with CO pi* AO giving lower energy LUMO, enhances reactivity therefore attack anti to electronegative for best HOMO-LUMO overlap
3
Q
chelation control
A
used if there’s heteroatom with lp and a metal that can bin simultaneously to heteroatom and carbonyl
4
Q
common chelating metals
A
Small or highly charged:
Mg, Zn, Cu, Ti, Mn, Ce, sometimes Li
5
Q
common non-chelating metals
A
monocationic:
Li, Na and K
