Substituent Effects ACOC II

Alkyl

Sigma donor

O-

Sigma donor, π-donor

SiR3

Sigma donor

GeR3

Sigma donor

SnR3

Sigma donor

-I < Br < Cl < F (Halogens)

Sigma acceptor, π-donor

NR2 < OR < F < R3N+

Sigma acceptors, with NR2, OR and F also π-donors

C=C < Ph < C TB C

Sigma acceptors, with Ph and C=C as π-donors

SR

π-donor

C=O

Is π-acceptor

C=N-R

π-acceptor

-C TB N

Is π-acceptor

-NO2

Is π-acceptor

SO2R

Is π-acceptor

-S(=O)R

Is π-acceptor

Sigma - meta - acceptors: put into correct order:

F NR3+ H NO2 SO2Me CN Ph SOMe CF3 Br COMe Cl CO2Et OAc CO2H I CONH2 CCH NHAc OH CH=CH2 SMe OMe

NR3+ >> NO2 >> SO2Me > CN ~ SOMe > CF3 > Br ~ OAc ~ COMe ~ Cl ~ CO2Et ~ CO2H > I ~ F > CONH2

> CCH ~ NHAc ~ CH=CH2 > SMe > OH ~ OMe > Ph > H

Sigma meta - donor - put into correct order:

Me H CO2- Et NH2 tBu

H > Et ~ Me > tBu ~ CO2- > NH2

Sigma para - acceptors: put into correct order

NR3+ H NO2 OAc SO2Me CN Br Cl CF3 SOMe COMe CO2Et F COOH CONH2 CCH I CO2- H

NR3+ > NO2 > SO2Me > CN >> CF3 > COMe ~ SOMe > CO2Et ~ COOH > CONH2 > OAc > CCH ~ Cl ~ Br >

I >> F > CO2- ~ H

Sigma para - donors: put into correct order

NH2 OMe SMe Ph H NHAc Et CH=CH2 Me tBu OH

H ~ SMe ~ Ph ~ NHAc > CH=CH2 >> Et > Me > tBu > OMe >> OH >>> NH2