Synthesis of chiral chalcone derivatives catalyzed by the chiral cinchona alkaloid squaramide.
نویسندگان
چکیده
An effective method has been developed for the preparation of novel chiral chalcone derivatives under mild conditions from the easily accessible starting materials nitromethane and chalcone derivatives 2. The corresponding products were obtained in moderate yields with excellent enantioselectivities (up to 99%).
منابع مشابه
One-pot synthesis of novel chiral β-amino acid derivatives by enantioselective Mannich reactions catalyzed by squaramide cinchona alkaloids.
An efficient one-pot synthesis of novel β-amino acid derivatives containing a thiadiazole moiety was developed using a chiral squaramide cinchona alkaloid as organocatalyst. The reactions afforded chiral β-amino acid derivatives in moderate yields and with moderate to excellent enantioselectivities. The present study demonstrated for the first time the use of a Mannich reaction catalyzed by a ch...
متن کاملOrganocatalytic, enantioselective synthesis of benzoxaboroles via Wittig/oxa-Michael reaction Cascade of α-formyl boronic acids.
An unprecedented enantioselective synthesis of 3-substituted benzoxaboroles has been developed. An in situ generated ortho-boronic acid containing chalcone provides the chiral benzoxaboroles via an asymmetric oxa-Michael addition of hydroxyl group attached to the boronic acid triggered by the cinchona alkaloid based chiral amino-squaramide catalysts. In general, good yields with good to excelle...
متن کاملEnantioselective synthesis of α-deuterium labelled chiral α-amino acids via dynamic kinetic resolution of racemic azlactones.
Catalytic dynamic kinetic resolution (DKR) of racemic azlactones with EtOD using squaramide-based dimeric cinchona alkaloid organocatalysts is shown to be a highly effective strategy for the preparation of enantiomerically pure α-deuterated chiral α-amino acids.
متن کاملSynthetic studies on (+)-biotin, part 15: A chiral squaramide-mediated enantioselective alcoholysis approach toward the total synthesis of (+)-biotin.
An efficient stereocontrolled total synthesis of (+)-biotin (1) has been achieved via the intermediacy of Roche's lactone 5 starting from cis-1,3-dibenzyl-2-imidazole-4,5-dicarboxylic acid (2). The bifunctional cinchona alkaloid-derived squaramide-promoted enantioselective alcoholysis was utilizing as a tool for the construction of two contiguous stereocenters of C-3a and C-6a in biotin molecul...
متن کاملEnantioselective synthesis of gamma-hydroxyenones by chiral base-catalyzed Kornblum DeLaMare rearrangement.
A cinchona-alkaloid catalyzed asymmetric Kornblum DeLaMare rearrangement has been developed. Thus, enantioenriched 4-hydroxyenones are prepared from dienes by a two-step sequence involving photochemical dioxygenation and chiral base-catalyzed desymmetrization of the resulting endoperoxides.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Molecules
دوره 19 12 شماره
صفحات -
تاریخ انتشار 2014