Wittig Reaction

Mechanism of the Wittig Reaction

Sample reactions

TMS2NK, Ph3P+CH2OMe Cl-
THF
-78 °C to RT, ON, 75% (2 steps)


Ph3P
THF
Reflux, 3 h, 81%


KOt-Bu, Ph3P+CH3 Br-
THF
0 °C to RT, 13 h, 73% (2 steps)



Dimsyl sodium
DMSO
80% (3 steps)



DME
Reflux, , 79%


Ph3P=CH2
THF
0 °C to RT, , 92%


n-BuLi, Ph3P+CH3 Br-
THF
-78 °C to RT, 3.5 h, 95%


i-Pr2NLi, Ph3P(CH2)6CO2H+ Br-
THF
-78 °C to RT, 7.5 h, 67%


TMS2NK, Ph3P+CH2O(CH2)2TMS Cl-
THF
-78 °C to RT, 45 min



TMS2NNa
DME
-78 to 0 °C, 85 min, 76% (2 steps)


Ph3P+CH3 Br-, TMS2NNa
THF
36% (2 steps)


Ph3P=CH2
THF
85% (2 steps)


Ph3P=CMe2
THF
0 °C, 14 h, 57% (3 steps)


TMS2NNa, Ph3P+CH3 I-
THF
-78 to 0 °C, 90 min


Ph3P=CH2
THF
-78 to 0 °C, 25 min, 77%


TMS2NK, Ph3P+CH2OMe Cl-
THF
-78 °C to RT, 85 min, 91%



n-BuLi
THF
-78 °C to RT, ON, 89%
"Ratio of the cis-cis, cis-trans, trans-cis and trans-trans isomers, respectively."


n-BuLi, Ph3P+CH3 Br-
DMSO, THF
80 °C, 3.5 h


Ph3P=CH2
DMSO
75 °C, 16 h


TMS2NK, Ph3P+CH2OMe Cl-
PhMe
0 to 120 °C, 4 h



PhH
90 °C, 90 min, 98%



MeOH
0 °C to RT, 12 h, 74% (2 steps)


n-BuLi, Ph3P+CH3 Br-
THF
0 °C, 3 h, 96%



LiOEt
CH2Cl2, EtOH
71% (2 steps)



TMS2NNa
THF
-78 °C to RT, ON, 59% (2 steps)
"Aqueous HCl work-up cleaves the THP."



TMS2NNa
THF
-78 °C to RT, ON, 80% (2 steps)



PhH
80 °C, 15 h, 81% (2 steps)



CH2Cl2
40 °C, 60 min, 89 % (3 steps)



CH2Cl2
3.5 h, 86%



n-BuLi
Et2O, THF
RT to Reflux, 2 d, 96%


Ph3P+CH3 Br-, NaOt-Amyl
PhMe
RT, 90 min, 88%



n-Bu3P, NaBH(OAc)3
CH2Cl2
RT, 17 h, 79%


n-BuLi, Ph3P+CH3 Br-
THF
RT, 95 min, 96%


n-BuLi, Ph3P+CH3 Br-
THF
70 °C, 15 h, 77%



TMS2NK
PhMe
RT, 12 h, 80%


n-BuLi, Ph3P+CH3 Br-
THF
66% (2 steps)


n-BuLi, Ph3P+CH3 Br-
THF



TMS2NNa
THF
-78 °C to RT, 4 h, 92%


TMS2NK, Ph3P+CH2OMe Cl-
CH2Cl2, THF
-30 °C to RT, 15.5 h, 95%


TMS2NK, Ph3P+CH2OMe Cl-
CH2Cl2, THF
-50 °C to RT, 15 h, 74% (2 steps)


KOt-Bu, Ph3P+CH3 Br-
THF
65 °C, 2 h, 76%



n-BuLi
Et2O
0 °C to RT


(COCl)2, DMSO, Et3N, Ph3P=CHCO2Et
CH2Cl2
-65 °C to RT, 5 h


Ph3P+CH3 Br-, NaOt-Amyl
PhH
80 °C, 60 min, 92%


Ph3P+CH3 Br-, NaOt-Amyl
PhH
RT, 2 h, 92%


Ph3P=CH2


Ph3P=CH2
DMSO
70%


Ph3P+CH3 Br-, NaOt-Amyl
PhMe
RT to Reflux, 3 h, 84%


Ph3P=CH2
"No yield reported."


KOt-Bu, Ph3P+CHBr2 Br-
THF
RT, 12 h, 78% (2 steps)


Ph3P+CH3 Br-, NaOt-Amyl
PhMe
RT to reflux, 4 h, 80%



TMS2NNa
THF
-78 °C to RT, ON, 61%



PhH
RT to Reflux, 6 h, 81%


TMS2NK, Ph3P+CH3 Br-
THF
0 °C to RT, 30 min, 86%


KH, Ph3P+CH3 Br-
PhH, t-BuOH
RT to Reflux, 6 h, 93%


n-BuLi, Ph3P+CH3 Br-
Et2O
RT to Reflux, 90 min, 82%


KOt-Bu, Ph3P+CH2OMe Cl-
PhH
RT, 24 h



KOt-Bu
THF
0 °C, 30 min, 81% (2 steps)


TMS2NLi, Ph3P+CH2I I-
HMPA, THF
-78 °C to RT, 60 min


KOt-Bu, Ph3P+CH3 Br-
PhH
RT to Reflux, 21.5 h, 36% (2 steps)


KOt-Bu
PhH
Reflux, 24.5 h, 50%


Ph3P=CHOMe
THF
71%


KOt-Bu
PhH
50 to 70 °C, 7 h, 65%


Ph3P=CHCN
PhMe
80 °C, 2 h, 73% (3 steps)


Reflux, 24 h


NaH
DMSO
RT to 75 °C, 16 h, 62%


n-BuLi, Ph3P+CHMe2 Br-
THF
0 to 10 °C, 60 min, 86%



PhLi
Et2O, THF
-70 to -30 °C, 10 min


CH2Cl2
0 °C, 3 h, 76% (2 steps)


KOt-Bu, Ph3P+CH3 Br-
PhMe
0 °C to reflux, 3 h, 87%


H2O, H2SO4, KOt-Bu, Ph3P+CH2OMe Cl-
THF
0 °C to RT, 3.5 h, 68%


KOt-Bu, Ph3P+CH3 Br-
PhH, t-BuOH
RT to Reflux, 90 min, 63%



CH2Cl2
Reflux, 4 d, 97%
"93:07 E/Z"


Ph3P+CH3 Br-, TMS2NNa
THF
0 °C to RT, 13 h, 60%


Ph3P, CBr4
CH2Cl2
0 °C, 35 min, 94%


Ph3P=CHCO2Me
CH2Cl2
RT, 12 h, 82% (2 steps)


KOt-Bu, Ph3P+CH3 Br-
THF
0 °C to RT, 2 h, 87%


KOt-Bu, Ph3P+CH3 Br-
PhMe
reflux, 20 min, 96%


n-BuLi, Ph3P+CH3 Br-
THF
0 °C to RT, 2.5 h, 53%


n-BuLi, Ph3P+CH3 Br-
-15 to 0 °C, 95 min, 72%


CH2Cl2
0 °C, 12 h, 93%
