Angewandte Chemie International Edition

Fuchibe, Kohei; Kaneko, Tsukasa; Mori, Keiji; Akiyama, Takahiko

doi: 10.1002/anie.200904020pmid: N/A

N‐Fused indoles appear in the structures of various biologically active molecules, but synthesis of the fused‐ring substructure has proved difficult. T. Akiyama and co‐workers describe in their Communication on page 8070 ff. a new route in which a niobium carbenoid is generated by niobium‐catalyzed activation of the normally inactive C–F bonds of a CF3 group. The carbenoid then undergoes insertion into a neighboring C(sp3)H bond adjacent to a nitrogen atom to furnish the N‐fused indole skeleton.

Henke, Patrick; Pankewitz, Tobias; Klopper, Wim; Breher, Frank; Schnöckel, Hansgeorg

doi: 10.1002/anie.200904023pmid: N/A

Snapshots of the formation of a σ bond in Al2R4 isomers are obtained by structural and quantum chemical investigations, as described by H. Schnöckel, W. Klopper, and co‐workers in their Communication on page 8141 ff. By employing R=PtBu2, they succeeded in isolating a triplet molecule exhibiting a long AlAl separation as a first step. A bicyclic butterfly molecule rather than the unbridged R2AlAlR2 isomer represents the ground state. The ring‐inversion isomers are separated by a “wing beat” and a transition state.

doi: 10.1002/anie.200990222pmid: N/A

doi: 10.1002/anie.200990223pmid: N/A

doi: 10.1002/anie.200904969pmid: N/A

“The most significant advances in chemistry of this century have been the advances made in organocatalysis. The biggest challenge facing chemists is to regain acceptance in the general public. …︁” This and more about Gerhard Hilt can be found on page 7964.

Scott, Lawrence T.; Steinberg, Brian D.; Quimby, Jennifer M.; Fort, Eric H.; Greene, Allison K.; Smith, Natalie J.; Eliseeva, Maria N.

doi: 10.1002/anie.200903810pmid: N/A

Wiley‐VCH, Weinheim 2009. 471 pp., hardcover € 159.00.—ISBN 978‐3527317677

Duncan, Kelly

doi: 10.1002/anie.200903833pmid: N/A

Royal Society of Chemistry, Cambridge 2009. 514 pp., hardcover $ 299.00.—ISBN 978‐1847558992

Engels, Bernd; Christl, Manfred

doi: 10.1002/anie.200902263pmid: 19760684

Reaction rates of 1,3‐dipolar cycloadditions correlate closely with the energy required to distort the 1,3‐dipole and dipolarophile to the transition‐state geometry (see scheme). A bridge can be built connecting these new findings to the traditional frontier molecular orbital theory, which was and still is enormously successful in the rationalization of 1,3‐dipolar cycloadditions.

Koester, Dennis C.; Werz, Daniel B.

doi: 10.1002/anie.200903773pmid: 19735082

New approaches! Sometimes there is no harm in questioning established protocols and to think about completely new strategies. Here a new method makes possible the construction of all‐carbon quaternary stereocenters within aldol patterns in a sequential, one‐pot procedure starting from simple compounds such as alkynes (see scheme).

Driver, Tom G.

doi: 10.1002/anie.200904344pmid: 19780090

Activate that bond! The functionalization of the CF3 groups is an ongoing synthetic challenge owing to the inert nature of the CF bond. The aryl trifluoromethyl group can be reduced by a low‐valent niobium catalyst to produce a carbenoid that inserts into a C(sp3)H bond to produce complex, functionalized N‐fused indoles (see scheme).