A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• tert-butyloxycarbonyl-protected and deprotected 2-nitro-intermediates 20 and 21, respectively [23][24][25]. The nitro group was then selectively reduced using trichlorosilane and N,N-diisopropylethylamine (DIPEA) to form benzyl-protected 1-deazaguanine 22 [26]. Finally, the O6-benzyl moiety was cleaved

• ). Reduction: The mixture from the above procedure was suspended in dry dichloromethane (8 mL) at 0 °C, and N,N-diisopropylethylamine (DIPEA, 1.06 g, 1.43 mL, 8.21 mmol) was added. A solution containing dry dichloromethane (4 mL) and trichlorosilane (HSiCl3, 778 mg, 581 µL, 5.74 mmol) was prepared at 0 °C

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• , including enantioselective H-bonding-catalyzed additions to aliphatic N-Boc-imines with high stereoselectivity [22]. A broad range of β-aminonitroolefins were reduced to chiral β-aminonitroalkanes in high yields and excellent enantioselectivities using trichlorosilane as a reducing agent and an N

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• corresponding phosphine 4 (94%) by treatment with trichlorosilane, without affecting the (arylmethylene)cyclopropane moiety (Scheme 4). The great efficiency of the [2,3]-sigmatropic rearrangement of phosphinites 2a–h lacking substituents at C3 is in striking contrast with the reactivity of phosphinites

Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

• Riccardo Porta,
• Alessandra Puglisi,
• Giacomo Colombo,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2016, 12, 2614–2619, doi:10.3762/bjoc.12.257

• Riccardo Porta Alessandra Puglisi Giacomo Colombo Sergio Rossi Maurizio Benaglia Dipartimento di Chimica, Università di Milano, Via Golgi 19, 20133, Milano, Italy 10.3762/bjoc.12.257 Abstract The metal-free reduction of nitro compounds to amines mediated by trichlorosilane was successfully

• synthetically relevant intermediates (precursors of baclofen and boscalid). Keywords: chemoselectivity; continuous processes; flow synthesis; nitro reduction; trichlorosilane; Introduction The reduction of nitro compounds to amines is a fundamental transformation in organic synthesis. The nitration of

• plethora of further synthetic elaborations. Among the different available methodologies for the reduction of nitro compounds [8], we have recently reported a very convenient, mild, metal-free and inexpensive procedure, of wide applicability [9][10]. The simple combination of trichlorosilane (HSiCl3) and a

Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

• Rajesh Munirathinam,
• Roberto Ricciardi,
• Richard J. M. Egberink,
• Jurriaan Huskens,
• Michael Holtkamp,
• Herbert Wormeester,
• Uwe Karst and
• Willem Verboom

Beilstein J. Org. Chem. 2013, 9, 1698–1704, doi:10.3762/bjoc.9.194

• (Enschede, The Netherlands). Synthesis of the catalytic polymer coating Immobilization of the trichlorosilane initiator and the polymer brushes synthesis on the silicon oxide surface [19][20] and the microchannels [16] were carried out following literature procedures. A solution of styrene sulfonate (1.25 g

Enantioselective reduction of ketoimines promoted by easily available (S)-proline derivatives

• Martina Bonsignore,
• Maurizio Benaglia,
• Laura Raimondi,
• Manuel Orlandi and
• Giuseppe Celentano

Beilstein J. Org. Chem. 2013, 9, 633–640, doi:10.3762/bjoc.9.71

• 10.3762/bjoc.9.71 Abstract The behavior of readily synthesized and even commercially available (S)-proline derivatives, was studied in the trichlorosilane-mediated reduction of ketoimines. A small library of structurally and electronically modified chiral Lewis bases was considered; such compounds were

• studies were also performed in order to elucidate the origin of the stereoselection. Keywords: chiral prolines; imine reduction; Lewis bases; organocatalysis; trichlorosilane; Introduction The reaction with stoichiometric amounts of trichlorosilane in the presence of a chiral catalyst is a well

• selectivity was achieved by tuning the metal catalyst. In the trichlorosilane-mediated reductions in this work we aimed to exploit the imine activation by the acid proton of the carboxylic group, which can act at the same time as a Lewis basic site to coordinate the silicon atom and hopefully control the

Reciprocal polyhedra and the Euler relationship: cage hydrocarbons, C_nH_n and closo-boranes [B_xH_x]²⁻

• Michael J. McGlinchey and
• Henning Hopf

Beilstein J. Org. Chem. 2011, 7, 222–233, doi:10.3762/bjoc.7.30

• , 72, and E = Ge, 73, where R is again a bulky group, are also well-known (Scheme 15). Indeed, octakis(t-butyldimethylsilyl)octasilane, (72a), is obtained in 72% yield by treatment of the corresponding trichlorosilane precursor with sodium in toluene at 90 °C. These systems have been thoroughly

Enantioselective synthesis of tricyclic amino acid derivatives based on a rigid 4-azatricyclo[5.2.1.0^2,6]decane skeleton

• Matthias Breuning,
• Tobias Häuser,
• Christian Mehler,
• Christian Däschlein,
• Carsten Strohmann,
• Andreas Oechsner and
• Holger Braunschweig

Beilstein J. Org. Chem. 2009, 5, No. 81, doi:10.3762/bjoc.5.81

• trichlorosilane in the presence of a catalytic amount of [Pd(C3H5)Cl]2 and (R)-MOP [(R)-2-diphenylphosphino-2′-methoxy-1,1′-binaphthyl], followed by SiCl3/OH exchange, delivered the exo-alcohol 12 in 81% yield and 85% ee, as determined from the (S)- and (R)-Mosher esters of 12. After oxidation (see Scheme 1), the

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• was investigated (Scheme 1). The first step, the reduction of (Sp,RS)-5 to sulfide (Sp)-6, proved the most problematic; use of a large excess of trichlorosilane and triethylamine resulted in deoxygenation in moderate yield after recrystallisation [40]. By comparison, reduction of the less hindered

• by sulfinyl-directed ortho lithiation with n-butyllithium followed by reaction with tosyl azide. The resulting azo[2.2]paracyclophane was reduced in situ to give the amine (Rp,RS)-8 in good yield for the two steps (Scheme 2). Trichlorosilane-mediated deoxygenation proceeded uneventfully to furnished

• , 207 [[2.2]paracyclophane]+, 152, 136, 123, 104, 91, 78 (Found: [M]+, 312.1545. C20H24OS requires [M]+, 312.1542). (Sp)-(+)-4-tert-Butylsulfanyl[2.2]paracyclophane [(Sp)-6] Triethylamine (11.92 mL, 85.58 mmol, 10 equiv) was added to a solution of trichlorosilane (17.9 mL, 128.36 mmol, 15 equiv) and (Sp