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In this paper, we give an operator parameterization for the set of dilations of a given pair of dual g-frames and the set of dilations of pairs of dual g-frames of a given g-frame. In particular, for the dilations of a given pair of dual g-frames, we introduce the concept of joint complementary g-frames and prove that the joint complementary g-frames of a pair of dual g-frames are unique in the sense of joint similarity, which then helps to obtain a sufficient condition such that the complementary g-frames of a g-frame are unique in the sense of similarity and show that the set of dilations of a given dual g-frame pair are parameterized by a set of invertible diagonal operators. For the dilations of pairs of dual g-frames, we prove that the set of dilations of pairs of dual g-frames are parameterized by a set of invertible upper triangular operators. [ABSTRACT FROM AUTHOR]

A novel protocol for the transamidation of DMF and derivatives with weakly nucleophilic anilines has been developed, utilizing a catalytic amount of Pd(OAc) 2 and 2,2′-bipyridine, and with PivOH and BF 3 ·Et 2 O as additives. This methodology has a broad substrate scope, and various corresponding transamidation products were prepared in good to excellent yields from commercially available DMF derivatives and anilines. The synthetic utility of the reported protocol was further demonstrated with a gram-scale experiment. Control experiments suggested the efficient transformation of DMF and derivatives with anilines might owe to the synergistic effect of palladium complex, PivOH, and BF 3 ·Et 2 O. [ABSTRACT FROM AUTHOR]

Abstract: Asymmetric addition of terminal alkynes to allenyl aldehydes took place in the presence of an acetylacetonate complex [Rh(acac)L∗] (L∗=binap or segphos) as a catalyst to give indanol derivatives in high yields with high regio- and enantioselectivity. The acetylacetonate (acac) ligand on the rhodium is important for the selective formation of the indanol derivatives. [ABSTRACT FROM AUTHOR]

Asymmetric hydrosilylation of styrene derivatives with trichlorosilane in the presence of palladium complexes of chiral spiro phosphoramidites provided 1-aryl-1-silylalkanes as single regioisomers in high yields, which have been oxidized with hydrogen peroxide to give the corresponding chiral alcohols in up to 99.1% ee. [Copyright &y& Elsevier]

A cobalt‐catalyzed annulation of o‐phenylenediamines and internal alkynes for the synthesis of quinoxalines is developed. This method provides a variety of quinoxalines in good to high yields under a simple and mild reaction conditions with molecular O2 as a terminal oxidant. Preliminary mechanistic studies show that a novel reaction mechanism is involved in the current reaction, which is different from the previous reported dicarbonyl compound mechanism via the oxidation of the alkyne. [ABSTRACT FROM AUTHOR]

The scalable reaction tolerates a broad range of functional groups. [ABSTRACT FROM AUTHOR]

Review: 178 refs. [ABSTRACT FROM AUTHOR]

The method provides a simple and efficient approach to various 3,4-disubstituted isocoumarins which are of biological interest. [ABSTRACT FROM AUTHOR]

A novel decarboxylative N -arylation of indole-2-carboxylic acids with aryl halides is developed. The reaction proceeds efficiently in the presence of Cu2 O as the catalyst to give the corresponding N -aryl indoles in high yields. This synthetic method shows good functional group tolerance and offers an alternative route to construct N -aryl indoles. [ABSTRACT FROM AUTHOR]

The synthesis of N-heterocycles of quinoxalines has been developed by an efficient protocol of one-pot annulation of alkynes with o-phenylenediamines. A variety of quinoxalines were prepared in good to high yields in the presence of catalytic amount of iodine as a catalyst. [ABSTRACT FROM AUTHOR]

The direct oxidation of internal alkynes proceeds efficiently in the presence of CuI as a catalyst to afford the corresponding 1,2-diketones in good yields. This strategy offers a simple and efficient route for the synthesis of 1,2-diketones from an inexpensive copper catalyst and easily available internal alkynes. The advantage of present protocol is further demonstrated by the synthesis of quinoxaline derivatives from alkynes and 1,2-diaminobenzene via one-pot procedure. [ABSTRACT FROM AUTHOR]

An abstract of the article "Enantioselective Synthesis of 3-Alkynyl-3-hydroxyindolin-2-ones by Copper-Catalyzed Asymmetric Addition of Terminal Alkynes to Isatins" by Ning Xu and colleagues is presented.

The efficient title reaction uses catalytic amounts of an inexpensive copper catalyst and shows a good functional group tolerance of aryl alkynes. [ABSTRACT FROM AUTHOR]