A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates

• Erwan Le Gall,
• Antoine Pignon and
• Thierry Martens

Beilstein J. Org. Chem. 2011, 7, 997–1002, doi:10.3762/bjoc.7.112

• -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates is described. This route involves the formation of an imine, which is used without isolation, followed by its activation by the carbonyl-containing electrophile and the trapping of the acyliminium by an organozinc reagent. Most

• steps are conducted concomitantly to render the procedure as practical and straightforward as possible. Therefore, the whole experimental protocol takes less than two hours. Keywords: acyliminium; amides; carbamates; multicomponent reactions; organozinc reagents; Introduction Diarylmethylamines

• ], or organozinc compounds [24][25]. However, although these are recognized as mild multi-purpose reagents, sole examples of their use in nucleophilic additions on acylimium salts consist, to the best of our knowledge, of the phenylation of quinolinium salts using diphenylzinc [26][27]. Recently, our

Recent advances in carbocupration of α-heterosubstituted alkynes

• Ahmad Basheer and
• Ilan Marek

Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77

• sulfoxides 36 in quantitative yields (Scheme 19) [37][38][39][40] that can be further used in organic synthesis [41][42][43]. However, to obtain functionalized dialkylated ethylenic sulfoxide species, the addition of functionalized organozinc species is required. Upon treatment with (FG-R2)2Zn (2 equiv) or

A short and efficient synthesis of valsartan via a Negishi reaction

• Samir Ghosh,
• A. Sanjeev Kumar and
• G. N. Mehta

Beilstein J. Org. Chem. 2010, 6, No. 27, doi:10.3762/bjoc.6.27

• , the use of organozinc compounds provides better transmetalation activity than that obtained by the use of organoboron reagents as well as good chemoselectivity since most common functional groups are not attacked by organozinc species. Although preparations of several biphenyl ring systems related to

• -pentanoyl-L-valinate (5) [9] in 70% yield. Ortho-metalation of 5-phenyl-1-trityl-1H-tetrazole (6) [10] with n-butyllithium at 25 °C followed by treatment with zinc chloride at −20 °C gave the desired organozinc chloride compound. Coupling of the latter with aryl bromide 5 in presence of a catalytic amount

Continuous flow enantioselective arylation of aldehydes with ArZnEt using triarylboroxins as the ultimate source of aryl groups

• Julien Rolland,
• Xacobe C. Cambeiro,
• Carles Rodríguez-Escrich and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2009, 5, No. 56, doi:10.3762/bjoc.5.56

• ]. On the other hand, enantioselective arylation of aldehydes with organozinc reagents appears as a most convenient alternative, since the initial aldehyde undergoing addition presents two very different groups (namely, a H atom and an aryl group) and hence offers good opportunities for enantiocontrol

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• stereoselective addition of the organozinc reagent 305 to aldehyde 304. The ester 308 was condensed with the TBS ether of (S)-lactic aldehyde 309 to afford the γ-lactone adduct 310. Exposure of the alcohol 310 to trifluoroacetic anhydride and triethylamine led to the triol 300a. 10(S)-Asimin (300b) was prepared

• from aldehyde 304 by an identical sequence, using the enantiomer of 306 in the addition of the organozinc reagent. By comparing the MTPA ester of diastereomeric alcohols 300a and 300b with the authentic MTPA ester, the stereochemistry at C-10 of asimin (300) assigned as R. Total synthesis of bullatacin

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

A superior P-H phosphonite: Asymmetric allylic substitutions with fenchol- based palladium catalysts

• Bernd Goldfuss,
• Thomas Löschmann,
• Tina Kop-Weiershausen,
• Jörg Neudörfl and
• Frank Rominger

Beilstein J. Org. Chem. 2006, 2, No. 7, doi:10.1186/1860-5397-2-7

• Leeuwen's bulky, monodentate TADDOL based phosphoramidite gave rise to intriguing memory effects [28b] and yielded 6% branched product with 25% ee (Scheme 2) [9]. We have recently employed modular, chelating fencholates, [10][11][12][13][14] in enantioselective organozinc catalysts, [15][16][17][18][19] 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

• recently applied in chiral organolithium reagents [52][53][54][55][56][57][58] and in organozinc [59][60][61][62] as well as in organopalladium catalysts [63][64][65][66][67] to study origins of enantioselectivities in C-C-couplings. The rigid, terpene-based bicyclo[2.2.1]heptane unit enables efficient