Efficient and general conditions for the formation of stereodefined trisubstituted alkenes by using the rhodium‐catalyzed reaction of unactivated Baylis–Hillman adducts with either organoboronic acids or potassium trifluoro(organo)borates are reported (see scheme).
Block copolymers in seconds : Catalyst‐free, ambient‐temperature click conjugation of individual polymer strands becomes possible using novel ATRP‐derived cyclopentadienyl‐capped polymers in an extremely rapid hetero‐Diels–Alder cycloaddition with macromolecules equipped with electron‐deficient dithioester end groups prepared by the RAFT process.
Systemic change : A system of transformations between helical structures was observed to be governed by interactions mediated by the electronic effects of substituents, entropic effects, the conformational preferences of organic building blocks, and the coordinative preferences of the metal ion. All of these effects were important, but all must be considered together to allow the prediction of the product observed (see scheme).
A dramatic effect is observed when acyclic N‐(2‐naphthamides) of medium‐chain 1‐amino‐2‐methylalkanes are partially ordered with the help of liposomes: the Cotton effect arising from π–π* transitions of the terminal naphthamide chromophor is enormously enhanced. This effect was exploited to assign the configuration of new polyketide peroxides such as 1 from the sponge Plakortis halichondroides.
Pd doles it out : A palladium‐catalyzed approach to indoles using the title reaction was achieved (see scheme). The oxidant used in this catalytic cycle was O2. Both N‐nonsubstituted and N‐alkyl monosubstituted anilines can be successfully transformed into the corresponding indoles by this method.
Caught in the middle : The ionomycin calcium complex (see structure; O red, Ca green) was the target of an approach featuring the efficient asymmetric synthesis of an allene by a copper(I)‐mediated anti‐selective SN2′ reaction, a highly stereoselective gold(III)‐catalyzed cycloisomerization of an α‐hydroxyallene, and a Rh‐catalyzed rearrangement of an α‐diazo‐β‐hydroxyketone.
Bright lights : Fullerene–silica hybrid nanoparticles have bright photoluminescence, high photostability, and low cytotoxicity, which are assets for bioimaging agents. The origin of the photoluminescence of the nanoparticle is the C–O–Si bond (see picture).
Economical approach : The first organocatalytic asymmetric intramolecular hydroarylation of phenol‐ and aniline‐derived enals offers one of the most straightforward and atom‐economic approaches to enantioriched chromans and tetrahydroquinolines (up to 96 % ee; see scheme).
Locked in translation : Crucial insight into the ribosomal catalysis of peptide‐bond formation is expected to be gained from the target compounds, which feature conformational locking in a North‐type pucker, designed to interfere with the translation of the genetic code. The compounds were prepared from D ‐ribose in 18 and 19 steps by a multi‐step synthetic route described here (see scheme).
A process of elimination : Optical spectra of the Br2 product eliminated from the photodissociation of 1,1‐dibromoethylene at 248 nm are obtained (see picture), and the subsequent dissociation pathways are proposed with the aid of ab initio potential energy calculations. The behavior of the compound is compared with that of 1,2‐dibromoethylene.
Dipolar aggregation : Examples of a novel class of tweezer molecules have been constructed through the tethering of two dipolar merocyanine chromophores. The electrostatic‐interaction‐directed self‐assembly of these tweezers affords centrosymmetric bimolecular complexes with a unique aggregate geometry of four π‐stacked chromophores (see picture) with an alternating arrangement of their dipole moments and very high dimerization constants, even in the good solvating solvent chloroform.
Curvy ligands for H 2 storage? Enhancement of H2 adsorption has been observed in coordination framework materials, an example of which is depicted, by the introduction of phenanthrene and 9,10‐dihydrophenanthrene groups into porous CuII–carboxylate framework materials of NbO topology.
The moderate nucleophilicity of the axially chiral amino sulfonamide (S)‐ 1 suppresses the problematic side reactions, including aldol reactions, in the asymmetric Mannich reaction of N‐Boc‐protected imines with aldehydes. The corresponding adducts are obtained in good yield and excellent stereoselectivity (see scheme; Boc=tert‐butoxycarbonyl, Tf=trifluoromethanesulfonyl).
Linked‐in : The rigid Schiff‐base ligand cis,trans‐1,3,5‐tris(pyridine‐2‐carboxaldimino) cyclohexane (ttop) is synthesized, and its complexation to copper(II) salts at a range of stoichiometries is investigated crystallographically by using electrospray mass spectrometry. Further, in‐situ mass spectrometry measurements allow the stepwise construction of the complexes to be observed.
