Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira–Glaser cyclization sequence

• Dominik Urselmann,
• Dragutin Antovic and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1499–1503, doi:10.3762/bjoc.7.174

• efficiency is also variable. Just recently we reported a very straightforward one-pot synthesis of symmetric 1,4-di(hetero)arylated 1,3-butadiynes starting from (hetero)aryl iodides by virtue of a sequentially Pd/Cu-catalyzed [14] Sonogashira–Glaser process (Scheme 1) [15]. According to this general one-pot

• concatenation of our sequentially Pd/Cu-catalyzed Sonogashira–Glaser reaction [15] with the sulfide-mediated cyclization should lead to a straightforward one-pot pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes (Scheme 2). We first set out to identify an optimal cosolvent for all four steps

• symmetrical 2,5-di(hetero)arylthiophenes based upon an initial sequentially Pd/Cu-catalyzed Sonogashira–Glaser process followed by a subsequent sulfide-mediated cyclization. A broad range of functional groups is tolerated and the iodo substrates are either commercially available or easily accessible. This

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• completion. A variety of amines were involved in this one-pot sequential three-component reaction allowing the introduction of different protecting groups of the indole moiety. This site-selective, Pd/Cu-catalyzed cross-coupling approach was also performed on 1-chloro-2-iodo-4-(trifluoromethyl)benzene as o

Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis

• Inhee Cho,
• Labros Meimetis,
• Lee Belding,
• Michael J. Katz,
• Travis Dudding and
• Robert Britton

Beilstein J. Org. Chem. 2011, 7, 1315–1322, doi:10.3762/bjoc.7.154

• diiodohydrobenzoin 12 in Cu-catalyzed C–N cross-coupling reactions [33] led only to the formation of cis-4b,9b-dihydrobenzofuro[3,2-b]benzofuran (24) [34]. Consequently, the diol 12 was converted to the corresponding acetonide 25 or methyl ether 26 prior to cross-coupling. In this manner, the diphenylhydrobenzoin

Combined directed ortho-zincation and palladium-catalyzed strategies: Synthesis of 4,n-dimethoxy-substituted benzo[b]furans

• Verónica Guilarte,
• M. Pilar Castroviejo,
• Estela Álvarez and
• Roberto Sanz

Beilstein J. Org. Chem. 2011, 7, 1255–1260, doi:10.3762/bjoc.7.146

• corresponding coupled products 5–7 by using the Pd/TBAF method A, with no significant side-products (Table 2, entries 1,2,7,8 and 14). However, under these conditions bromine-containing compounds 4b,d and f afforded variable amounts of dialkynylation products in some cases, and so the Pd/Cu catalyzed procedure

Directed aromatic functionalization

• Victor Snieckus

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

• exchange) chemistry, alternative and competitive combinational metal amide bases are rapidly appearing [47][48]. The first successful glimpses of the much sought after complementary, cleaner, regiodefined, and milder procedures to ortho, para versus meta SEAr reactions are being seen in Cu-catalyzed meta

One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• novel concept combines the unique reactivity patterns of transition metal catalysis with fundamental organic reactivity, in a sequential or consecutive fashion. Over the years, we have contributed to this concept through Pd/Cu-catalyzed accesses to enones and ynones and the in situ transformation of

• , followed by Pd/Cu-catalyzed decarbonylative alkynylation with terminal alkynes 2, and finally by cyclocondensation of the ynone intermediates with substituted amidine hydrochlorides 4, pyrimidylazulenes 5 were obtained in moderate to good yields in a one-pot fashion (Scheme 5) (for experimental details

Control of asymmetric biaryl conformations with terpenol moieties: Syntheses, structures and energetics of new enantiopure C₂-symmetric diols

• Y. Alpagut,
• B. Goldfuss and
• J.-M. Neudörfl

Beilstein J. Org. Chem. 2008, 4, No. 25, doi:10.3762/bjoc.4.25

• enantioselective organozinc catalysts [14][15][16][17][18], in chiral n-butyllithium aggregates [19][20][21][22][23] and in enantioselective Pd- and Cu-catalyzed C-C-couplings [9][10][24]. Here we present syntheses and characterizations of new enantiopure C2-symmetric diols based on (−)-menthone, (−)-verbenone and

An exceptional P-H phosphonite: Biphenyl- 2,2'-bisfenchylchlorophosphite and derived ligands (BIFOPs) in enantioselective copper- catalyzed 1,4-additions

• T. Kop-Weiershausen,
• J. Lex,
• J.-M. Neudörfl and
• B. Goldfuss

Beilstein J. Org. Chem. 2005, 1, No. 6, doi:10.1186/1860-5397-1-6

• enantioslective Cu-catalyzed 1,4-additions. Results and Discussion Coupling of bis-lithiated biphenyl-2,2'-bisfenchol (BIFOL), synthesized from 2,2'-dilithiobiphenyl and (-)-fenchone, [68][69][70][71][72] with PCl3 or PBr3 yields the enantiopure halophosphites BIFOP-Cl, 1 (62% yield) and BIFOP-Br, 2 (69% yield

• ', Scheme 4). The tightest encapsulation and fenchane embedding of phosphorus atoms is apparent for the halophosphites BIFOP-Cl (1, 2.471 Å) and BIFOP-Br (2, 2.476 Å, Table 2), explaining their unusual low reactivity (Table 1). Cu-catalyzed, enantioselecitve 1,4-additions of diethylzinc to 2-cyclohexene-1

• -Et phosphonite BIFOP-Et (4) during Cu-catalyzed 1,4-additions of diethylzinc to cyclohexenone, the P-H phosphonite BIFOP-H (3) is stable and gives even a higher enantioselectivity than a corresponding phosphite or phosphoramidite. Hence, the large steric demand and the relatively low accessibility of