227778-64-5

Upstream product

• 1520-21-4 4-vinyl benzylamine 
• 501-53-1 benzyl chloroformate 
• 13139-17-8 N-(Benzyloxycarbonyloxy)succinimide 
• 371153-68-3 4-benzyloxycarbonylaminophenylacetylene 
• 3422-03-5 benzyloxycarbonyl azide 
• 2156-04-9 4-Vinylphenylboronic acid 
• 92159-87-0 benzyl (4-bromophenyl)carbamate 
• 75927-49-0 pinacol vinylboronate 

Downstream Products

• 93008-63-0 N-(benzyloxycarbonyl)-4-ethylaniline 
• 589-16-2 4-aminoethylbenzene 
• 1427737-85-6 (E)-benzyl (4-(4,4,4-trifluorobut-1-en-1-yl)phenyl)carbamate 
• 1422040-86-5 C₄₂H₄₅N₅O₄ 
• 1422041-09-5 C₁₆H₁₉N₃ 
• 1422041-02-8 C₂₄H₂₃N₃O₄ 
• 1422041-01-7 C₂₃H₂₁N₃O₄ 

Relevant academic research and scientific papers

Interrogating Pd(II) Anion Metathesis Using a Bifunctional Chemical Probe: A Transmetalation Switch

Ligand metathesis of Pd(II) complexes is mechanistically essential for cross-coupling. We present a study of halide→OH anion metathesis of (Ar)PdII complexes using vinylBPin as a bifunctional chemical probe with Pd(II)-dependent cross-coupling pathways. We identify the variables that profoundly impact this event and allow control to be leveraged. This then allows control of cross-coupling pathways via promotion or inhibition of organoboron transmetalation, leading to either Suzuki-Miyaura or Mizoroki-Heck products. We show how this transmetalation switch can be used to synthetic gain in a cascade cross-coupling/Diels-Alder reaction, delivering borylated or non-borylated carbocycles, including steroid-like scaffolds.

A synthetic approach to N -aryl carbamates via copper-catalyzed Chan-Lam coupling at room temperature

A mild and efficient synthesis of N-arylcarbamates was achieved by reacting azidoformates with boronic acids in the presence of 10 mol % of copper chloride catalyst. The reaction proceeds readily in an open flask at room temperature without additional base, ligand, or additive. Rapid access to urea analogues via a two-step one-pot procedure is enabled by reacting N-arylcarbamates with aluminum-amine complexes. In addition, among several boronic acid derivatives prepared, dimethylphenyl boronate was found to react rapidly in its reaction with benzyl azidoformate, invoking in situ generation of this species in the catalytic cycle.

Easily-controlled chemoselective hydrogenation by using palladium on boron nitride

The hydrogenation catalyzed heterogeneously by palladium on boron nitride (Pd/BN) in methanol realized the chemoselective hydrogenation of only azides, alkenes, and alkynes in the presence of other reducible functionalities such as benzyl ethers, aryl halides, aryl ketones, and nitro groups. Furthermore, the totally chemoselective semihydrogenation of alkynes could also be achieved without the reduction of other coexisting reducible functionalities, which include azides and alkenes, by using Pd/BN in pyridine as a solvent. Be unique, be selective: The chemoselective hydrogenation of azides, alkenes, and alkynes was achieved without the reduction of other reducible functionalities by the use of a heterogeneous palladium on boron nitride (Pd/BN) catalyst. Furthermore, Pd/BN was applicable to the unique and chemoselective semihydrogenation of alkynes without the reduction of azido functionalities in the presence of pyridine or diethylenetriamine.

Development of a palladium on boron nitride catalyst and its application to the semihydrogenation of alkynes

The simple preparative method for a novel palladium supported on boron nitride catalyst (Pd/BN) was accomplished. Pd/BN is widely applicable for the semihydrogenation of mono- as well as disubstituted alkynes to furnish the corresponding alkenes in the presence of diethylenetriamine (DETA), which exhibits both an unprecedented acceleration effect toward the semihydrogenation and a suppression effect with regard to the overhydrogenation to alkanes. Copyright

Partial hydrogenation of alkynes to cis-olefins by using a novel Pd 0-polyethyleneimine catalyst

The creation and application of a new Pd0-polyethyleneimine complex catalyst (Pd0-PEI) was investigated. The 55 Pd 0-PEI catalyst was prepared by introduction of Pd(OAc)2 directly in the MeOH solution of deaerated PEI under Ar atmosphere. Reactions were carried out using 10 weight % versus substrate of 5% Pd0-PEI in 2mL solvent under H2 atmosphere at room temperature. The generality of the process was shown by disubstituting alkynes. Even for the substrate bearing a conjugated ketone on the alkyne, the serious over-reduction was not observed while significant cistrans isomerization of methyl styryl ketone accompanied the partial hydrogenation on the basis of keto-enol tautomerism. Pd0-PEI catalyst is also applicable to the partial hydrogenation of monosubstituted alkynes to monosubstituted olefins.

Chemoselective hydrogenation method catalyzed by Pd/C using diphenylsulfide as a reasonable catalyst poison

While Pd/C is one of the most useful catalysts for hydrogenation, the high catalyst activity of Pd/C causes difficulty in its application to chemoselective hydrogenation between different types of reducible functionalities. In order to achieve chemoselective hydrogenation using Pd/C, we investigated catalyst poison as a controller of the catalyst activity. We found that the addition of Ph2S (diphenylsulfide) to the Pd/C-catalyzed hydrogenation reaction mixture led to reasonable deactivation of Pd/C. By the use of the Pd/C-Ph2S catalytic system, olefins, acetylenes, and azides can be selectively reduced in the coexistence of aromatic carbonyls, aromatic halides, cyano groups, benzyl esters, and N-Cbz (benzyloxycarbonyl) protecting groups. The present method is promising as a general and practical chemoselective hydrogenation process in synthetic organic chemistry.

Pd/C-catalyzed chemoselective hydrogenation in the presence of diphenylsulfide

A Pd/C-catalyzed chemoselective hydrogenation using diphenylsulfide as a catalyst poison has been developed. This methodology selectively hydrogenates olefin and acetylene functionalities without hydrogenolysis of aromatic carbonyls and halogens, benzyl esters, and N-Cbz protective groups.

Highly chemoselective hydrogenation method using novel finely dispersed palladium catalyst on silk-fibroin: Its preparation and activity

A palladium-fibroin complex (Pd/Fib) was prepared by soaking silk-fibroin in MeOH solution of Pd(OAc)2 for 2 days (under Ar atmosphere) - 4 days (under air). Pd(OAc)2 was gradually absorbed by fibroin and the rapid reduction of fibroin conjugated Pd(OAc)2 proceeded with MeOH as a reductant at room temperature to be the Pd(0) complex. Pd/Fib catalyzed chemoselective hydrogenation of acetylenes, olefins and azides in the presence of aromatic ketones and aldehydes, halides, N-Cbz protective groups and benzyl esters which are readily hydrogenated using Pd/C or Pd/C(en) as a catalyst.

Pd/C(en)-catalyzed chemoselective hydrogenation with retention of the N-Cbz protective group and its scope and limitations

A chemoselective method for the hydrogenation of acetylene, olefin, azide, nitro and benzyl ester functionalities with retention of the aliphatic N-Cbz group was established. The chemoselectivity was accomplished by using a combination of 5% Pd/C-ethylenediamine [5% Pd/C(en)] and THF (or 1,4-dioxane) as a solvent, and the scope and limitations of this methodology were investigated. These results reinforce the utility of N-Cbz protective groups in synthetic chemistry, especially in peptide synthesis. (C) 2000 Elsevier Science Ltd.

Asymmetric synthesis of conformationally restricted L-arginine analogues as active site probes of nitric oxide synthase

Using the catalytic asymmetric sharpless carbamate aminohydroxylation, conformationally restricted L-arginine and L-homoarginine derivatives (5-8) were prepared in good enantiomeric excess to investigate the binding requirements of L-arginine-based compounds with nitric oxide synthase. The L- arginine derivatives (5 and 6) inhibited both the inducible and neuronal isoforms of nitric oxide synthase with little isoform selectivity (5, IC50 = 42 and 144 μM, 6, 8 and 12 μM, respectively). The guanidine-containing compound (5) did not act as a nitric oxide producing substrate for nitric oxide synthase. The ability of these compounds to interact with the enzyme supports the idea that L-arginine-based inhibitors bind to the enzyme in a folded conformation. The L-homoarginine derivatives (7 and 8) did not interact with the enzyme as either substrates or inhibitors. The two-carbon L-arginine homologue (9), prepared from L-phenylalanine, demonstrated the greatest isoform selective inhibition of the compounds examined (IC50(iNOS) = 19 and IC50(nNOS) = 147 μM, IC50(nNOS)/IC50i(NOS) = 7.7). These results suggest isoform selective inhibition may be related to the folded conformations required for binding of these higher L-arginine homologues.