Change in rate-determining step for a simple carbonyl addition reaction. Kinetically significant proton transfer step in acid-catalyzed O-methyloxime formation

1973 ◽  
Vol 95 (15) ◽  
pp. 5073-5075 ◽  
Author(s):  
Samuel M. Silver ◽  
Jane M. Sayer
Keyword(s):  
Proton Transfer ◽  
Addition Reaction ◽  
Rate Determining Step ◽  
Transfer Step ◽  
Acid Catalyzed ◽  
Carbonyl Addition ◽  
Significant Proton

Study of the Wallach rearrangement and related processes in the 100% sulfuric acid region

1970 ◽  
Vol 48 (2) ◽  
pp. 377-382 ◽  
Author(s):  
E. Buncel ◽  
W. M. J. Strachan
Keyword(s):  
Sulfuric Acid ◽  
Proton Transfer ◽  
Kinetic Method ◽  
Rate Data ◽  
Upper Limit ◽  
Transfer Step ◽  
Rearrangement Process ◽  
Equilibrium Process ◽  
Acid Catalyzed ◽  
Acid Region

Study of the acid-catalyzed Wallach rearrangement of azoxybenzene is extended into the 100% H2SO4 region. The rate of formation of 4-hydroxyazobenzene can be followed spectrally in a straight-forward manner until close to 99% H2SO4, but in higher acidities sulfonation of this product becomes kinetically important. The advent of second equilibrium protonations of 4-hydroxyazobenzene and of 4-hydroxyazobenzene-4′-slfonic acid further complicate the azoxybenzene rearrangement as followed spectrally. Above 100% H2SO4 a second sulfonation is also observed. A method is given for dissecting the rate data for the primary rearrangement process from the first of the sulfonation reactions.The rate of the azoxybenzene rearrangement is observed to increase continuously up to 99.99% H2SO4 (the upper limit of the present kinetic method). This suggests that the second proton transfer step to azoxybenzene is rate-determining and not an equilibrium process. These results permit a clarification of a previously proposed mechanism (1).

Evidence for two concurrent mechanisms and a kinetically significant proton transfer process in acid-catalyzed O-methyloxime formation

1974 ◽  
Vol 96 (26) ◽  
pp. 7986-7998 ◽  
Author(s):  
S. Rosenberg ◽  
S. M. Silver ◽  
J. M. Sayer ◽  
W. P. Jencks
Keyword(s):  
Proton Transfer ◽  
Transfer Process ◽  
Acid Catalyzed ◽  
Significant Proton ◽  
Proton Transfer Process

scholarly journals Catalytic Enantioselective Synthesis of 4-Amino-1,2,3,4-tetrahydropyridine Derivatives from Intramolecular Nucleophilic Addition Reaction of Tertiary Enamides

Synlett ◽  
2018 ◽  
Vol 30 (04) ◽  
pp. 483-487 ◽  
Author(s):  
Shuo Tong ◽  
Mei-Xiang Wang
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Catalysis ◽  
Nucleophilic Addition ◽  
Addition Reaction ◽  
Enantioselective Synthesis ◽  
Chiral Phosphoric Acid ◽  
Substrate Engineering ◽  
Nucleophilic Addition Reaction ◽  
Engineering Strategy ◽  
Acid Catalyzed

A general and efficient method for the synthesis of highly enantiopure 4-amino-1,2,3,4-tetradydropyridine derivatives based on chiral phosphoric acid catalyzed intramolecular nucleophilic addition of tertiary enamides to imines has been developed. We have also demonstrated a substrate engineering strategy to significantly improve the enantioselectivity of asymmetric catalysis

Nonenforced catalysis of the bisulfite carbonyl addition reaction by hydrogen bonding

1977 ◽  
Vol 99 (4) ◽  
pp. 1206-1214 ◽  
Author(s):  
P. R. Young ◽  
W. P. Jencks
Keyword(s):  
Hydrogen Bonding ◽  
Addition Reaction ◽  
Carbonyl Addition
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