Catalytic Asymmetric 6π-Electrocyclization: Accessing Highly Substituted Optically Active 2-Pyrazolines via Diastereoselective Alkylations
作者:Benjamin List、Steffen Müller
DOI:10.1055/s-0029-1218792
日期:2010.7
The chiral phosphoric acid catalyzed asymmetric electrocyclization of α,β-unsaturated hydrazones has been studied. This reaction is one of the first catalyticasymmetric 6π-electrocyclizations reported, and enables the synthesis of 2-pyrazolines in high yields and enantiomeric ratios. The obtained products are not only interesting because of their pharmaceutical properties, but can be manipulated in
作者:Romero Reyes, Moises A.、Dutta, Subhradeep、Odagi, Minami、Min, Chang、Seidel, Daniel
DOI:10.1039/d4sc04760e
日期:——
A new conjugate-base-stabilized carboxylic acid (CBSCA) containing a 3,5-bis(pentafluorosulfanyl)phenylthiourea functionality catalyses challenging one-pot condensations/6π-electrocyclizations of hydrazines and α,β-unsaturated ketones under mild conditions. Structurally diverse N-aryl 2-pyrazolines are obtained in good yields and enantioselectivities. The superior performance of 3,5-bis(SF5)phenylthioureas