Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands

• Laurence Bonnafoux,
• Frédéric R. Leroux and
• Françoise Colobert

Beilstein J. Org. Chem. 2011, 7, 1278–1287, doi:10.3762/bjoc.7.148

• stereoelectronic profile of a ligand. Most frequently, biaryls are prepared through transition metal-catalyzed reactions of suitable functionalized starting materials [17][18][19][20][21][22]. Although these methods are well established, alternatives are investigated in order to avoid expensive transition metals

Directed aromatic functionalization

• Victor Snieckus

Beilstein J. Org. Chem. 2011, 7, 1215–1218, doi:10.3762/bjoc.7.141

• insertion, the gates of the synthetic arena were spectacularly opened to the 2010 Nobel Prize chemistry and the general theme of transition metal-catalyzed reactions. Thus, the named reactions of Kumada–Corriu, Negishi, Suzuki–Miyaura, Stille and, most recently, Hiyama have all given new insights into how

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• (Scheme 59) [174]. The first step is supposed to be an intramolecular addition of the hydroxy group to the internal carbon of the triple bond, which is similar to the mechanism mentioned above [161][163]. 6 Gold-catalyzed asymmetric addition reactions The chiral ligand used for the transition metal

• -catalyzed reactions are the main determinant of enantioselectivity. Although asymmetric catalysis using chiral organometal complexes and chiral organomolecules have shown many advantages and a range of catalytic asymmetric reactions have been well documented [175], gold-catalyzed asymmetric addition

When cyclopropenes meet gold catalysts

• Frédéric Miege,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2011, 7, 717–734, doi:10.3762/bjoc.7.82

• versatile reactivity in transition metal-catalyzed reactions [15]. As has been observed with other transition metals, the reactivity of cyclopropenes A in gold-catalyzed reactions is essentially (but not exclusively) related to their ability to act as ligands for π-acidic gold complexes, and hence, to

• , depending on the substitution pattern [35][36]. Due to their high strain and π-electron density, cyclopropenes exhibit reactivity often comparable to that of alkynes in transition metal-catalyzed reactions. Not surprisingly, the reactivity of cyclopropenylmethyl carboxylates in the presence of gold

Gold-catalyzed heterocyclizations in alkynyl- and allenyl-β-lactams

• Benito Alcaide and
• Pedro Almendros

Beilstein J. Org. Chem. 2011, 7, 622–630, doi:10.3762/bjoc.7.73

• metal-catalyzed reactions of α-allenols which afford heterocyclization products, intramolecular cyclizations of γ-allenols have also attracted a great deal of interest [45][46][47]. A study of the regioselectivity control during the gold-catalyzed O–C functionalization of 2-azetidinone-tethered γ

• was catalyzed by gold salts (AuCl3), allene cycloisomerization adducts 7 were obtained as the sole isomers (Scheme 3). The cyclization of allenyl-β-lactams 5 is an application of the previously reported gold-catalyzed cycloisomerization of α-hydroxyallenes [42][43][44]. Similarly to the transition

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• (in the case of transition metal-catalyzed reactions) also can be problematic in large-scale syntheses, especially in pharmaceutical applications. Consequently, reactions based on the use of supported catalysts are in many ways a more attractive option for the stereoselective synthesis of chiral

Mixtures of monodentate P-ligands as a means to control the diastereoselectivity in Rh-catalyzed hydrogenation of chiral alkenes

• Manfred T. Reetz and
• Hongchao Guo

Beilstein J. Org. Chem. 2005, 1, No. 3, doi:10.1186/1860-5397-1-3

• diastereoselectivity of transition metal catalyzed reactions of chiral substrates. This was accomplished by studying the diastereoselective Rh-catalyzed hydrogenation of the chiral allylic alcohol 1 and the homo-allylic alcohol 5. Since the goal was proof-of-principle, only 23 randomly chosen monodentate P-ligands

• conclusion, the previous concept of using mixtures of monodentate ligands in order to influence enantio-[19][20][21][22][23][24][25][26] and regioselectivity [28] of transition metal catalyzed reactions has been extended to include diastereoselectivity. The idea of using mixtures of monodentate ligands in a

• combinatorial manner is rapidly emerging as a powerful method to enhance activity and selectivity of transition metal-catalyzed reactions. Diastereoselective hydrogenation of the allylic alcohol 1. Diastereoselective hydrogenation of the homo-allylic alcohol 5. Acknowledgements Generous support from the Fonds