Rh(III)-catalyzed directed C–H bond amidation of ferrocenes with isocyanates

• Satoshi Takebayashi,
• Tsubasa Shizuno,
• Takashi Otani and
• Takanori Shibata

Beilstein J. Org. Chem. 2012, 8, 1844–1848, doi:10.3762/bjoc.8.212

• ] catalyzed the C–H bond amidation of ferrocenes possessing directing groups with isocyanates in the presence of 2 equiv/Rh of HBF4·OEt2. A variety of disubstituted ferrocenes were prepared in high yields, or excellent diastereoselectivities. Keywords: amidation; C–H activation; C–H functionalization

Copper-catalyzed CuAAC/intramolecular C–H arylation sequence: Synthesis of annulated 1,2,3-triazoles

• Rajkumar Jeyachandran,
• Harish Kumar Potukuchi and
• Lutz Ackermann

Beilstein J. Org. Chem. 2012, 8, 1771–1777, doi:10.3762/bjoc.8.202

• fully substituted 1,2,3-triazoles with excellent chemo- and regioselectivities. Likewise, the optimized catalytic system proved applicable to the direct preparation of 1,2-diarylated azoles through a one-pot C–H/N–H arylation reaction. Keywords: cascade reaction; C–H functionalization; copper

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• . Keywords: alkenylation; arylation; C–H functionalization; indoles; N–H functionalization; Pd catalysis; Introduction The development of mild and selective reactions for the direct conversion of carbon–hydrogen bonds into carbon–carbon and carbon–heteroatom bonds is a challenging goal in organic chemistry

• of C–H functionalization on unactivated substrates typically occur with electrophilic Pd(II) catalysts and require an oxidizing agent in order to make possible the reoxidation of the Pd(0) species, generated in the final elimination step, for a new catalytic cycle [12][13][14][15]. The well

• providing conditions to access asymmetric biaryl compounds by dual C–H functionalization [55]. In 2007, Fagnou and co-workers combined, in a single catalytic cycle, the reactivity of electron-deficient palladium(II) complexes with electron-rich arenes (through an electrophilic C–H activation mechanism) and

Extending the utility of [Pd(NHC)(cinnamyl)Cl] precatalysts: Direct arylation of heterocycles

• Anthony R. Martin,
• Anthony Chartoire,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2012, 8, 1637–1643, doi:10.3762/bjoc.8.187

• investigated. Among four different precatalysts, [Pd(SIPr)(cinnamyl)Cl] proved to be the most efficient promoter of the reaction. The C–H functionalization of sulfur- or nitrogen-containing heterocycles has been achieved at low catalyst loadings. These catalyst charges range from 0.1 to 0.01 mol % palladium

• . Keywords: C–H functionalization; direct arylation; heterocycles; N-heterocyclic carbenes; palladium; Introduction As a powerful addition to the classic palladium cross-coupling reactions, C–H bond functionalization has become a growing field of research over the last few years. The ubiquity of C–H bonds

• observed in 3. With complexes 1–4 in hand, their catalytic activity towards the direct arylation of heteroaromatic compounds was evaluated. For this purpose, the arylation of benzothiophene (6) with 4-bromotoluene (7) was selected as a benchmark reaction (Table 2). This C–H functionalization, initially

Synthesis of conformationally restricted glutamate and glutamine derivatives from carbonylation of orthopalladated phenylglycine derivatives

• Esteban P. Urriolabeitia,
• Eduardo Laga and
• Carlos Cativiela

Beilstein J. Org. Chem. 2012, 8, 1569–1575, doi:10.3762/bjoc.8.179

• results, however, in the formation of the cyclic isoindolinone or the open 2-carboxyphenylglycine methyl esters, with the reaction outcome being driven by the choice of the solvent. Keywords: C–H functionalization; carbonylation; glutamic acid; glutamide; palladium; phenylglycine; Introduction The

Arylglycine-derivative synthesis via oxidative sp³ C–H functionalization of α-amino esters

• Zhanwei Xu,
• Xiaoqiang Yu,
• Xiujuan Feng and
• Ming Bao

Beilstein J. Org. Chem. 2012, 8, 1564–1568, doi:10.3762/bjoc.8.178

• phenols with α-amino esters proceeded smoothly in the presence of meta-chloroperoxybenzoic acid as an oxidant under ambient conditions, to produce arylglycine derivatives in satisfactory yields. Keywords: α-amino ester; arylglycine; C–H functionalization; oxidation; synthesis; Findings Arylglycine

• -(disubstituted amino)acetates with naphthols and phenols. The proposed coupling reaction proceeded smoothly in the presence of mCPBA as an oxidant under ambient conditions to provide arylglycine derivatives in satisfactory yields. Synthesis of arylglycine derivatives. Oxidative sp3 C–H functionalization of α

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

• demonstrate that the resultant reactivity may be a powerful tool for the functionalization of C–H and E–H bonds. Keywords: ambiphilic reactivity; C–H activation; C–H functionalization; frustrated Lewis pair; metal carbene; multiple bond; Introduction Orbital cooperation has long been recognized as an

• high oxidation states that are attached to π-basic ligands (i.e., Mδ+═Eδ−), and (2) late transition metals in low oxidation states attached to π-acidic ligands (i.e., Mδ−═Eδ+). The reactivity engendered by such a bonding situation can in some cases be quite useful in C–H functionalization schemes that

• processes in catalysis, in which only a few specialized systems have been reported to accomplish catalytic C–H functionalization [47][48][49]. In fact, the bond-breaking process across metal–ligand multiple bonds is closely related to σ-bond metathesis [43], highlighting the potential of Mδ+═Eδ− FLPs to

C–H Functionalization

• Huw M. L. Davies

Beilstein J. Org. Chem. 2012, 8, 1552–1553, doi:10.3762/bjoc.8.176

• Huw M. L. Davies Department of Chemistry, Emory University, 440 Atwood Hall, 1515 Dickey Drive, Atlanta GA 30322, USA 10.3762/bjoc.8.176 Keywords: C–H Functionalization; C–H Functionalization has the potential to become a paradigm-shifting strategy for organic synthesis. Over the last decade

• , the field has experienced explosive growth and a large variety of new C–H functionalization methodologies have been developed. In particular, regioselective functionalization of sp2 C–H bonds has become a broadly flexible approach for the synthesis of complex aromatic carbocycles and heterocycles. In

• can become broadly applicable. Metal-bound carbenes, nitrenes and oxo species have been particularly effective at stereoselective sp3 C–H functionalization. However, considerable advances still need to be made to enhance the selectivity and to increase the range of functionality that can be introduced

C2-Alkylation of N-pyrimidylindole with vinylsilane via cobalt-catalyzed C–H bond activation

• Zhenhua Ding and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2012, 8, 1536–1542, doi:10.3762/bjoc.8.174

• indoles in moderate to good yields. Keywords: alkylation; C–H functionalization; cobalt; indole; vinylsilane; Introduction The indole ring ubiquitously occurs in biologically active natural and unnatural compounds [1][2][3]. Consequently, there has been a strong demand for catalytic methods allowing

Sonogashira–Hagihara reactions of halogenated glycals

• Dennis C. Koester and
• Daniel B. Werz

Beilstein J. Org. Chem. 2012, 8, 675–682, doi:10.3762/bjoc.8.75

• functionalization allowed for the mild and selective borylation of unfunctionalized glycals. Starting from persilylated glycals Ishikawa and Miyaura applied an Ir-catalyzed C–H-functionalization with B2pin2 to obtain 1-borylated glycals, such as 3, in excellent yields and selectivity. They elegantly demonstrated

• co-workers utilized 1-stannylated glycals of type 1 in a Stille cross-coupling for the synthesis of aryl-C-glycosides such as 2 (R = Ar) [14][15]. To generate these 1-substituted glycals a prefunctionalization of the pseudoanomeric carbon is mandatory. Recent advances in the field of C–H

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

• catalytic amount of phosphite–gold(I) pre-catalyst and a silver additive. Notably, the addition is regioselective for the allene terminus, and generates (E)-allylation products 202. The direct C–H functionalization of indoles or pyrroles is an efficient method for the introduction of vinyl and aryl groups

• (Scheme 53). The latter is the first example of a gold-catalyzed intramolecular C–C cross-coupling reaction involving aryl C–H functionalization with Selectfluor® as the oxidant. 2,4-Dien-6-ynecarboxylic acids 316 undergo gold-catalyzed tandem 1,6-cyclization/decarboxylation to afford 2,3-disubstituted

Synthesis of dihydrophenanthridines by a sequence of Ugi-4CR and palladium- catalyzed intramolecular C-H functionalization

• Florence Bonnaterre,
• Michèle Bois-Choussy and
• Jieping Zhu

Beilstein J. Org. Chem. 2008, 4, No. 10, doi:10.3762/bjoc.4.10

• intramolecular C-H functionalization of these adducts under ligandless conditions provided the functionalized dihydrophenanthridines (1). Conclusion Highly functionalized dihydrophenanthridines are synthesized in only two steps from readily accessible starting materials in good to excellent overall yields

• a key intramolecular C-H functionalization reaction [13][14]. As a continuation of this research program, we were interested in the synthesis of dihydrophenanthridines 1 by combined use of Ugi-4CR and a palladium-catalyzed direct CH-arylation process. The synthetic sequence we envisioned is shown in