Asymmetric aldol reactions catalyzed by tryptophan in water.
نویسندگان
چکیده
Tryptophan was shown to be able to catalyze direct aldol reactions between various cyclic ketones and aromatic aldehydes in water with high enantioselectivity.
منابع مشابه
Acyclic amino acid-catalyzed direct asymmetric aldol reactions: alanine, the simplest stereoselective organocatalyst.
The linear amino acid-catalyzed direct asymmetric intermolecular aldol reaction is presented; simple amino acids such as alanine, valine, isoleucine, aspartate, alanine tetrazole and serine catalyzed the direct catalytic asymmetric intermolecular aldol reactions between unmodified ketones and aldehydes with excellent stereocontrol and furnished the corresponding aldol products in up to 98% yiel...
متن کاملOrganocatalytic direct asymmetric aldol reactions in water.
We have developed direct asymmetric cross-aldol reactions that can be performed in water without addition of organic solvents. A bifunctional catalyst with a long hydrophobic alkyl chain efficiently catalyzed the reactions and afforded the desired aldol products in excellent yield with high enantiomeric excess, even when only an equal molar ratio of the donor and acceptor was used. These result...
متن کاملChitosan Aerogel Catalyzed Asymmetric Aldol Reaction in Water: Highly Enantioselective Construction of 3-Substituted-3-hydroxy-2-oxindoles
A chitosan aerogel catalyzed asymmetric aldol reaction of ketones with isatins in the presence of water is described. This protocol was found to be environmentally benign, because it proceeds smoothly in water and the corresponding aldol products were obtained in excellent yields with good enantioselectivities.
متن کاملAsymmetric aldol reactions of α,β-unsaturated ketoester substrates catalyzed by chiral diamines.
Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system.
متن کاملsyn-Selective asymmetric cross-aldol reactions between aldehydes and glyoxylic acid derivatives catalyzed by an axially chiral amino sulfonamide.
syn-Selective asymmetric cross-aldol reactions of aldehydes with tert-butyl glyoxylate and glyoxamide were realized by the use of an axially chiral amino sulfonamide (S)-1. The cross-aldol products obtained are densely functionalized and readily converted to synthetically useful and important chiral building blocks such as γ-lactone and γ-lactam.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemical communications
دوره 26 شماره
صفحات -
تاریخ انتشار 2006