نتایج جستجو برای: heck cross
تعداد نتایج: 491365 فیلتر نتایج به سال:
The anions of PdCl(2)L(2) and Pd(OAc)(2), precursors of palladium(0) used in cross-coupling and Heck reactions, play a crucial role in these reactions. Tricoordinated anionic complexes Pd(0)L(2)Cl(-) and Pd(0)L(2)(OAc)(-) are the effective catalysts instead of the usually postulated Pd(0)L(2) complex. The anion ligated to the palladium(0) affects the kinetics of the oxidative addition to ArI as...
The carbon-carbon bond forming process is one of the most important transformations in organic synthesis aimed at the construction of complex molecules. In this regard, the Heck reaction poses as a pivotal synthetic methodology widely used for the formation of carbon-carbon bonds starting from olefins and an electrophile. An alternative of growing importance to the conventional Heck reaction wa...
The application of the [Pd{C6H3(CH2CH2NH2)-4-OMe-5-κ2-C,N}(μ-Br)]2 complex of 2-methoxyphenethylamine in the Heck coupling reaction was considered under both conventional and microwave irradiation conditions, and their results were compared. This complex is an efficient, stable and non-sensit...
Heck reactions were performed with 4-bromoacetophenone and n-butyl acrylate, yielding the trans-arylated acrylate ester with high selectivity. Pd–zeolite catalysts were compared with supported Pd metal catalysts. In order to obtain an active and heterogeneous catalyst, the preformed or in situ-formed catalytically active Pd0 species and the PdII intermediates must be sufficiently stabilized on ...
Two-phase frictional pressure drop data were obtained for condensation of carbon dioxide in single horizontal micro tube of inner diameter ranged from 0.6 mm up to 1.6 mm over mass flow rates from 2.5*10 to 17*10 kg/s and vapor qualities from 0.0 to 1.0. The inlet condensing pressure is changed from 33.5 to 45 bars. The saturation temperature ranged from -1.5 C up to 10 C. These data have then ...
In model studies towards the quaternary centre at the heart of diazonamide A (early structure 2; revised structure 1), cyclisations of the alkene-substituted iodoaryls 4, 13, 18 and 23, under Heck reaction conditions, were shown to lead to the corresponding benzodihydrofuran 5, benzofuranone 14 and the oxindoles 19 and 24 respectively, in 50-80% yield. Further manipulation of the benzodihydrofu...
During the past decades, building on the seminal contributions of Overman and Shibasaki, the asymmetric intramolecular Heck reaction has been successfully applied in natural product synthesis to install tertiary and quaternary stereocenters. In stark contrast, the intermolecular version of this asymmetric transformation has not reached the same level of development and its synthetic utility rem...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید