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In recent years, α-imino rhodium carbene complexes derived by ring-opening of N-sulfonyl-1,2,3-triazoles have attracted much attention from organic chemists. Many transformations of these species have been reported that involve, in most cases, nucleophilic attack at the carbene center of the α-imino rhodium carbene, facilitating the synthesis of a wide range of novel and useful compounds, particularly heterocycles. This Minireview mainly focuses on advances in the transformation of N-sulfonyl-1,2,3-triazoles during the past two years. [ABSTRACT FROM AUTHOR]

Cyclobutadiene rhodium complexes bear high potential for applications in organometallic synthesis and catalysis. We have found that the cyclobutadiene complexes with substitutionally labile p-xylene ligands [(C4R4)Rh( p-xylene)]+ can be synthesized in one step from the commercially available bis(ethylene) complex [{(C2H4)2RhCl}2], p-xylene, and internal alkynes. The replacement of p-xylene by various ligands provides a general access to other [(C4R4)Rh] compounds, such as [(C4R4)RhCl] x, [(C4R4)RhL3]+, [(C4R4)Rh(C5H5)], and [(C4R4)Rh(arene)]+. Complex [(C4Et4)Rh( p-xylene)]+ also catalyzes an unusual cycloisomerization of a 1,11-dien-6-yne into a bicyclic diene. [ABSTRACT FROM AUTHOR]

The first example of efficient asymmetric hydrogenation of challenging β-aryloxyacrylic acids was realized using a RhI-complex based on the heterocombination of a readily available chiral monodentate secondary phosphine oxide (SPO) and an achiral monodentate phosphine ligand as the catalyst. Excellent enantioselectivities (92->99 % ee) were achieved for a wide variety of chiral β-aryloxypropionic acids with minor aryloxy elimination in most cases. The resultant products were readily transformed into biologically active compounds through simple synthetic manipulations. [ABSTRACT FROM AUTHOR]