A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• “on water”. Reductive FC alkylation of arenes with benzaldehyde and acetophenone catalyzed by the Ir-carbene complex 33. Formal synthesis of 1,1-diarylalkanes from benzyl alcohols and styrenes. (A) Mo-catalyzed hydroarylation of styrenes and cyclohexenes. (B) Hydroalkylation–cyclization cascade

2-Phenyl- tetrahydropyrimidine- 4(1H)-ones – cyclic benzaldehyde aminals as precursors for functionalised β²-amino acids

• Markus Nahrwold,
• Arvydas Stončius,
• Anna Penner,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2009, 5, No. 43, doi:10.3762/bjoc.5.43

• temperature. Despite the success in condensing 3 and benzaldehyde (dimethylacetal), all attempts to condense 3 with closely related acetophenone dimethylketal did not lead to any cyclisation product. To facilitate our selective ring opening concept, the N3-nitrogen of 4 had to be protected as a carbamate

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

• unmodified silica lowered the activity of the catalyst system, presumably via adsorption of some of the Ru(II) catalyst. Under optimal flow conditions, the transfer hydrogenation of acetophenone in isopropanol (using a flow-reactor consisting of a column packed with a slurry of the immobilized catalyst

• ). Continuous-flow asymmetric cyclopropanation. Continuous asymmetric hydrogenation of dimethyl itaconate in scCO2. Continuous asymmetric transfer hydrogenation of acetophenone. Asymmetric epoxidation using a continuous flow membrane reactor. Enzymatic cyanohydrin formation in a microreactor. Resolution of (R/S

Part 3. Triethylborane- air: a suitable initiator for intermolecular radical additions of S-2-oxoalkyl- thionocarbonates (S-xanthates) to olefins

• Jean Boivin and
• Van Tai Nguyen

Beilstein J. Org. Chem. 2007, 3, No. 47, doi:10.1186/1860-5397-3-47

• consumed and only 12% of acetophenone (2b) were formed. Similarly, xanthate 3a, in the presence of olefin 12, succeeded in giving adduct 24a (47%, entry 10) accompanied by some p-methoxyacetophenone (3b) (26%). For these two substrates, comparison between experiments 7–10 showed a striking effect of the

The first organocatalytic carbonyl- ene reaction: isomerisation- free C-C bond formations catalysed by H-bonding thio- ureas

• Matthew L. Clarke,
• Charlotte E. S. Jones and
• Marcia B. France

Beilstein J. Org. Chem. 2007, 3, No. 24, doi:10.1186/1860-5397-3-24

• catalyse ene reactions between α-methylstyrene and ethyl glyoxylate, trifluoro-acetophenone, or α-bromopyruvate. However, we have not had success with transition metal catalysed ketone ene reactions using these latter two substrates either. These studies reveal that the scope of the organocatalytic

A convenient catalyst system for microwave accelerated cross- coupling of a range of aryl boronic acids with aryl chlorides

• Matthew L. Clarke,
• Marcia B. France,
• Jose A. Fuentes,
• Edward J. Milton and
• Geoffrey J. Roff

Beilstein J. Org. Chem. 2007, 3, No. 18, doi:10.1186/1860-5397-3-18

• evaluate this aspect, so we elected to investigate the effect of the boronic acid component using one aryl chloride substrate, 4-chloro-acetophenone. Representative results are compiled in Table 1. A range of boronic acids can be coupled with high conversion and good to excellent isolated yield for the

Trapping evidence for the thermal cyclization of di-(o-acetylphenyl)acetylene to 3,3'-dimethyl- 1,1'-biisobenzofuran

• Charles P. Casey,
• Neil A. Strotman and
• Ilia A. Guzei

Beilstein J. Org. Chem. 2005, 1, No. 18, doi:10.1186/1860-5397-1-18

• involving Pd(PPh3)4, CuI, and Et3N in toluene gave 2'-(trimethylsilylethynyl)acetophenone as a brown oil in 99% yield (See additional data file 1 for experimental details and spectral characterization of new compounds). Deprotection of 2'-(trimethylsilylethynyl)acetophenone was accomplished by reaction with