- Highly efficient chemoselective N-tert butoxycarbonylation of aliphatic/aromatic/heterocyclic amines using diphenylglycoluril as organocatalyst
-
An efficient approach for the Chemoselective N-tert-butoxycarbonylation of a variety of amines using diphenylglycoluril as organocatalyst has been described. For the first time, a plausible mechanism for the N-tert-butoxycarbonylation has been proposed using density functional theory (DFT) calculations supported by NMR studies. The reusability of the organocatalyst and observation of the desired N-Boc protected amines being formed without the formation of side products like urea, oxazolidinone, isocyanate, and N, N-di-Boc derivatives makes the present protocol desirable.
- Awasthi, Amardeep,Mukherjee, Anagh,Singh, Mandeep,Rathee, Garima,Vanka, Kumar,Chandra, Ramesh
-
-
- Decarboxylative Conjunctive Cross-coupling of Vinyl Boronic Esters using Metallaphotoredox Catalysis
-
The synthesis of complex alkyl boronic esters through conjunctive cross-coupling of vinyl boronic esters with carboxylic acids and aryl iodides is described. The reaction proceeds under mild metallaphotoredox conditions and involves an unprecedented decarboxylative radical addition/cross-coupling cascade of vinyl boronic esters. Excellent functional-group tolerance is displayed, and application of a range of carboxylic acids, including secondary α-amino acids, and aryl iodides provides efficient access to highly functionalized alkyl boronic esters. The decarboxylative conjunctive cross-coupling was also applied to the synthesis of sedum alkaloids.
- Aggarwal, Varinder K.,Duong, Vincent K.,Mega, Riccardo S.,Noble, Adam
-
supporting information
p. 4375 - 4379
(2020/02/11)
-
- N-Protection of amines using pyridinium 2,2,2-trifluoroacetate ionic liquid as an efficient and reusable catalyst
-
A simple, green, and efficient method for the N-tert-butoxycarbonylation of amines by pyridinium 2,2,2-trifluoroacetate ([Py][OTf]) as an efficient and reusable catalyst is reported. In general, electron donating groups on aryl group give rise to the higher yields than electron withdrawing groups. Clean reaction, short reaction times, high yields, reusability of catalyst, and easy preparation of it are some advantages of this work.
- Karimian, Somaye,Tajik, Hassan
-
p. 218 - 220
(2014/02/14)
-
- Pd-catalyzed Suzuki-Miyaura cross-coupling reactions between sulfamates and potassium Boc-protected aminomethyltrifluoroborates
-
Sulfamates were studied as the electrophilic partners in the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction with potassium Boc-protected primary and secondary aminomethyltrifluoroborates. A broad range of substrates was successfully coupled to provide the desired products. Complex molecules containing a new carbon-carbon bond and an aminomethyl moiety could be prepared through this developed method.
- Molander, Gary A.,Shin, Inji
-
p. 2534 - 2537
(2013/06/27)
-
- One-pot synthesis of α-amino acids from CO2 using a bismetal reagent with Si-B bond
-
In the presence of 1.1 equiv of PhMe2Si-Bpin, 5 equiv of CsF, and 20 mol % of TsOH·H2O, precursors of N-Boc-imines can be converted into the corresponding α-aryl or α-alkenyl glycine derivatives under gaseous CO2 in moderate-to-high yields with a single operation. α-Isobutenyl glycine thus obtained can be further derivatized into various types of α-amino acids including N-Boc-leucine, serine, and glycine derivatives in short steps.
- Mita, Tsuyoshi,Chen, Jianyang,Sugawara, Masumi,Sato, Yoshihiro
-
p. 6202 - 6205
(2013/02/23)
-
- Synthesis of arylglycine and mandelic acid derivatives through carboxylations of α-amido and α-acetoxy stannanes with carbon dioxide
-
Incorporation reactions of carbon dioxide (CO2) with N-Boc-α-amido and α-acetoxy stannanes were developed using CsF as a mild tin activator. Monoprotected α-amido stannanes could be used, and the corresponding arylglycine derivatives were obtained in moderate-to-high yields under 1 MPa (10 atm) of CO2 pressure. α-Acetoxy stannanes also underwent carboxylation to afford mandelic acid derivatives in excellent yields under ambient CO2 pressure. Both transformations enabled the synthesis of α-tertiary and α-quaternary carboxylic acid derivatives. In addition, the chirality of (S)-N-tert-butylsulfonyl-α- amido stannanes was transferred with up to 90% inversion of configuration at 100 °C.
- Mita, Tsuyoshi,Sugawara, Masumi,Hasegawa, Hiroyuki,Sato, Yoshihiro
-
experimental part
p. 2159 - 2168
(2012/06/01)
-
- One-pot synthesis of α-amino acids from imines through CO2 incorporation: An alternative method for strecker synthesis
-
Itas a gas: A novel one-pot process for the synthesis of α-amino acids from imine equivalents using CO2 gas as a carbon source has been developed. This reaction was made possible by the reagent combination of TMSSnBu3 and CsF (see scheme). Three successive reactions (imine formation, stannylation, and carboxylation) proceeded in the same flask under these conditions to give products in up to 79 % yield. Boc=tert-butoxycarbonyl, TMS=trimethylsilyl.
- Mita, Tsuyoshi,Chen, Jianyang,Sugawara, Masumi,Sato, Yoshihiro
-
p. 1393 - 1396
(2011/04/22)
-
- New synthesis of tic-hydantoins sigma-1 ligands and pharmacological evaluation on cocaine-induced stimulant effects
-
Activation of the newly identified σ1 chaperone protein is involved in several aspects of the psychostimulant and addictive effects of cocaine. The development of ligands that selectively target the σ1 protein may lead to putative potent anti-cocaine agen
- Toussaint,Debreu-Fontaine,Maurice,Melnyk
-
experimental part
p. 355 - 373
(2011/09/13)
-
- Amberlyst-15: a mild, efficient and reusable heterogeneous catalyst for N-tert-butoxycarbonylation of amines
-
A mild and versatile method has been developed for the chemoselective N-tert-butoxycarbonylation of amines in the presence of Amberlyst-15 under solvent-free condition. The method is general for the preparation of N-Boc derivatives of aliphatic (acyclic and cyclic) and aromatic amines.
- Kumar, K. Shiva,Iqbal, Javed,Pal, Manojit
-
experimental part
p. 6244 - 6246
(2010/01/11)
-
- A generic approach for the catalytic reduction of nitriles
-
The scope of nickel boride mediated reduction of nitriles has been extended further to allow the preparation of Boc protected amines via a mild catalytic process. It is noteworthy that the toxicity of this procedure is greatly reduced due to its catalytic
- Caddick, Stephen,Judd, Duncan B.,Lewis, Alexandra K. De K.,Reich, Melanie T.,Williams, Meredith R. V.
-
p. 5417 - 5423
(2007/10/03)
-
- Rapid access to N-Boc phenylglycine derivatives via benzylic lithiation reactions
-
We report a novel and efficient method for the enantioselective synthesis of N-Boc protected phenylglycines. Yields and enantiomeric ratios vary widely depending on the nature of the solvent, the substrate and on the method of forming the chiral complex. Results show that the major reaction pathway is an enantioselective deprotonation/substitution process. The enantioselectivity appears to be limited by the chiral discrimination ability of the s-BuLi-(-)-sparteine complex. The synthetic method described is one of the shortest route to useful enantioenriched N-Boc phenylglycine derivatives.
- Barberis, Claude,Voyer, Normand,Roby, Johanne,Chénard, Sylvain,Tremblay, Martin,Labrie, Philippe
-
p. 2965 - 2972
(2007/10/03)
-
- Convenient synthesis of protected primary amines form nitriles
-
Investigations into the use of nickel chloride and sodium borohydride for the reduction of nitriles showed the secondary amine dimers to be the major products under normal conditions. The addition of a suitable trapping agent, such as di-tert-butyl dicarbonate, allowed the isolation of the protected primary amines. (C) 2000 Elsevier Science Ltd.
- Caddick, Stephen,De K. Haynes, Alexandra K.,Judd, Duncan B.,Williams, Meredith R.V.
-
p. 3513 - 3516
(2007/10/03)
-