Asymmetric aldol reaction using boron enolates
نویسندگان
چکیده
منابع مشابه
The boron-mediated ketone-ketone aldol reaction
The first examples of the directed, boron-mediated aldol reaction between different ketones are presented. Transformation of a variety of ketones to their corresponding boron enolates with Chx2BCl/Et3N, followed by reaction with acceptor ketones in diethyl ether, and oxidation of the resultant boron aldolate (H2O2, MeOH/pH 7 buffer), provided the aldol addition products. The reaction was most f...
متن کاملAsymmetric aldol reaction via memory of chirality.
Asymmetric aldol reactions of α-amino acid derivatives via memory of chirality were developed. Chiral oxazolidones with contiguous tetra- and trisubstituted chiral centers were obtained in 78-94% ee by the asymmetric aldol reaction followed by intramolecular acylation.
متن کاملAn alternative approach to aldol reactions: gold-catalyzed formation of boron enolates from alkynes.
A new method for enolate generation via the gold-catalyzed addition of boronic acids to alkynes is reported. The formation of boron enolates from readily accessible ortho-alkynylbenzeneboronic acids proceeds rapidly with 2 mol % PPh(3)AuNTf(2) at ambient temperature. The enolates undergo aldol reaction with an aldehyde present in the reaction mixture to give cyclic boronate esters, which can be...
متن کاملTitanium enolates of thiazolidinethione chiral auxiliaries: versatile tools for asymmetric aldol additions.
[formula: see text] Asymmetric aldol additions using chlorotitanium enolates of thiazolidinethione propionates proceed with high diastereoselectivity for the "Evans" or "non-Evans" syn product depending on the nature and amount of the base used. With (-)-sparteine as the base, selectivities of 97:3 to > 99:1 were obtained for the Evans syn products with 2 equivalents of base and for the non-Eva...
متن کاملStudy of the lanthanide-catalyzed, aqueous, asymmetric Mukaiyama aldol reaction.
The development of efficient methods for the asymmetric Mukaiyama aldol reaction in aqueous solution has received great attention. We have developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lant...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature Protocols
سال: 2007
ISSN: 1754-2189,1750-2799
DOI: 10.1038/nprot.2007.372