Tandem multi-step synthesis of C-carboxyazlactones promoted by N-heterocyclic carbenes.
نویسندگان
چکیده
Cascade reaction sequences incorporating N-heterocyclic carbene-based organocatalysis have been developed that allow the direct preparation of a range of (+/-)-4-phenoxycarbonylazlactones in good isolated yields (66-84%) from the corresponding N-p-anisoyl amino acids.
منابع مشابه
Suzuki-Miyaura reactions catalyzed by C₂-symmetric Pd-multi-dentate N-heterocyclic carbene complexes.
Suzuki-Miyaura coupling reactions are promoted by Pd complexes ligated with C₂-symmetric multi-dentate N-heterocyclic carbenes derived in situ from Pd(OAc)₂ and imidazolium salts. Good to excellent yields were obtained for aryl bromides as substrates. Turnover numbers of up to 10⁵ could be achieved with 5 × 10⁻⁴ mol% of Pd(OAc)₂/1 × 10⁻³ mol% NHC precatalyst in 24 h.
متن کاملTransfer hydrogenation promoted by N-heterocyclic carbene and water.
N-Heterocyclic carbenes (NHCs) promote the transfer hydrogenation of various activated C=C, C=N, and N=N bonds with water as the proton source. The NHCs act as reducing reagents to be converted into their oxides. A detailed reaction mechanism is proposed on the basis of deuterium-labeling experiments.
متن کاملSynthesis of phosphorus esters by transesterification mediated by N-heterocyclic carbenes (NHCs).
The versatile nucleophilic organic catalysts N-heterocyclic carbenes (NHCs) have been shown to effectively mediate the transesterification of phosphorus esters under mild conditions; user-friendly imidazolium salts can also be employed as pre-catalysts.
متن کاملCerberus-type N-heterocyclic carbenes: synthesis and study of the first tritopic carbenes with D(3h)-symmetry.
The synthesis and characterization of tris(N-heterocyclic carbene)s with D(3h)-symmetry is reported; these tritopic molecules feature three independent carbene moieties that are geometrically isolated to prevent chelation.
متن کاملReaction of N-heterocyclic carbenes with chalcones leading to the synthesis of deoxy-Breslow intermediates in their oxidized form.
The synthesis of deoxy-Breslow intermediates in their oxidized form has been developed via the reaction of N-heterocyclic carbenes (NHCs) with chalcones. Moreover, the initial tetrahedral adduct formed from the 1,4-addition of NHCs to chalcones is also isolated.
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:
- Chemical communications
دوره 30 شماره
صفحات -
تاریخ انتشار 2008