TY - JOUR
T1 - Gold versus silver-catalyzed intermolecular hydroaminations of alkenes and dienes
AU - Giner, Xavier
AU - Nájera, Carmen
AU - Kovács, Gábor
AU - Lledõs, Agustí
AU - Ujaque, Gregori
PY - 2011/1/1
Y1 - 2011/1/1
N2 - Comparative studies about the hydroamination of unactivated alkenes and dienes catalyzed by either cationic gold(I) triphenyl phosphite complexes or silver salts were performed using sulfonamides, anilines and carbamates as nucleophiles. Gold-catalyzed reactions generally, need lower loadings than those carried out with silver salts. Simple alkenes react only with sulfonamides and weak aromatic amines such as p-nitroaniline, whereas for conjugated dienes carbamates can also be used. Carbon-carbon double bond isomerization is observed only with gold similarly to when triflic acid was used, affording mixtures of regioisomeric products in the same cases. Silver-catalyzed hydroaminations failed with terminal alkenes, except with styrenes. Conjugate dienes can be hydroaminated either at 85 °C in toluene or at room temperature in dichloromethane. Non-conjugated 1,4- and 1,5-dienes suffer double hydroamination leading to saturated N-tosylated heterocyclic amines The catalytic cycle for the silver(I)-catalyzed hydroamination process has been computationally analyzed, resembling gold(I)-catalyzed processes, although with some significant differences. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
AB - Comparative studies about the hydroamination of unactivated alkenes and dienes catalyzed by either cationic gold(I) triphenyl phosphite complexes or silver salts were performed using sulfonamides, anilines and carbamates as nucleophiles. Gold-catalyzed reactions generally, need lower loadings than those carried out with silver salts. Simple alkenes react only with sulfonamides and weak aromatic amines such as p-nitroaniline, whereas for conjugated dienes carbamates can also be used. Carbon-carbon double bond isomerization is observed only with gold similarly to when triflic acid was used, affording mixtures of regioisomeric products in the same cases. Silver-catalyzed hydroaminations failed with terminal alkenes, except with styrenes. Conjugate dienes can be hydroaminated either at 85 °C in toluene or at room temperature in dichloromethane. Non-conjugated 1,4- and 1,5-dienes suffer double hydroamination leading to saturated N-tosylated heterocyclic amines The catalytic cycle for the silver(I)-catalyzed hydroamination process has been computationally analyzed, resembling gold(I)-catalyzed processes, although with some significant differences. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
KW - alkenes
KW - dienes
KW - gold(I) complexes
KW - silver salts
KW - sulfonamides
U2 - 10.1002/adsc.201100478
DO - 10.1002/adsc.201100478
M3 - Article
VL - 353
SP - 3451
EP - 3466
JO - Advanced Synthesis and Catalysis
JF - Advanced Synthesis and Catalysis
SN - 1615-4150
IS - 18
ER -