HCOOH synthesis

Non-Thermal Plasma Synthesis of Formic Acid in CO2-H2O Mixture. Determine the minimum energy efficiency of the plasma-chemical HCOOH synthesis in the CO2-H2O mixture (9-60) required for effective hydrogen production in the double-step cycle (9-60) and (9-61). Assume that thermodynamically about 70% of the total energy required for hydrogen production from water should be consumed in this case for decomposition of formic acid (9-61) to form hydrogen and to recycle carbon dioxide back to the plasma process. 

Carbon monoxide, CO, is produced when carbon or organic compounds burn in a limited supply of air, as happens in cigarettes and badly tuned automobile engines. It is produced commercially as synthesis gas by the re-forming reaction (Section 14.3). Carbon monoxide is the formal anhydride of formic acid, HCOOH, and the gas can be produced in the laboratory by the dehydration of formic acid with hot, concentrated sulfuric acid ... 

Hydroxamic acids are an important class of compounds targeted as potential therapeutic agents. A-Fmoc-aminooxy-2-chlorotrityl polystyrene resin 61 allowed the synthesis and subsequent cleavage under mild conditions of both peptidyl and small molecule hydroxamic acids (Fig. 14) [70]. An alternative hydroxylamine linkage 62 was prepared from trityl chloride resin and tV-hydroxyphthalimide followed by treatment with hydrazine at room temperature (Scheme 30) [71]. A series of hydroxamic acids were prepared by the addition of substituted succinic anhydrides to the resin followed by coupling with a variety of amines, and cleavage with HCOOH-THF(l 3). 

Scheme 63. Stereoselective synthesis of sibiricine (352), sewercinine (353), raddeanone (354), raddeanine (318), raddeanidine (355), yenhusomidine (359), and yenhusomine (323). Reagents a, hv, 02, Rose Bengal, NaOMe, MeOH b, hv, MeOH c, NaBH4 d, HCHO, HCOOH e, Ac20, py f, CICOjEt g, MsCl h, KOH, aq EtOH i, HCHO j, NaBH3CN k, 10% HC1.

Scheme 10. Total synthesis of artemisinin by Schmid and Hofheinz. Conditions (i) ClCH20Me, PhN(CH3)2, DCM, rt. (ii) B2H6/THF, H2O2 (iii) PhCHzBr, KH, THF/DMF (iv) HCl, MeOH (v) PCC, DCM, rt. (vi) LDA, (E)-(3-iodo-l-methyl-l-propenyl)-trimethylsilane (vii) lithium methoxy(trimethylsily)methyhde (viii) Li/NH3 (ix) PCC DCM (x) m-CPBA, DCM (xi) -Bu4NF, THF, rt. (xii) O2 (methylene blue, DCM, rt.) (xiii) HCOOH, DCM.

Scheme 30. i) KF/K222, DMSO, 120°C, 40 - 45%, 18 min ii) MejSiCN, Znl2 10 min RT then LiAlH4 50°C, 10 min in) HCOOH 100 °C,5 min then semi preparative HPLC then chiral HPLC RCY 6 % for each enantiomer, 128 min total synthesis time... 

Nakai 124-126). UV and IR spectra of 78 and 81-83 are characteristic of lupinine alkaloids of the cytisine series containing an a-pyridine ring. MS fragmentation patterns are similar to those of cytisine alkaloids. The structures of these alkaloids were confirmed by synthesis from cytisine by reaction with HCOOH (81), (CHjCO) (78), C2H5Br (82), or CH2=CH—COCH3 (83). 

After separation of the desired major diastereoisomer 154, the removal of the chiral auxiliary furnished vinyl compound 151 in enantiomerically pure form. The latter was directly converted to the 9-membered lactam 144 in 58% yield via a palladium-catalyzed carbonylation (10 atm CO, HCOOH, DME, 150°C). Removal of the methyl ester as previously described furnished (-)-rhazinilam. This elegant work constitutes the first asymmetric total synthesis of the natural product. 

Butene-l,4-diones and 2-butyne-l,4-diones were converted into 2,5-diaryl- and 2,3,5-triarylfurans in high yields in the presence of HCOOH and a catalytic anaount of Pd on carbon under microwave-irradiation conditions <03JOC5392>. This procedure provides a new approach to the starting material used in the Paal-Knorr furan synthesis, as unsaturated diones are reduced to saturated diones in situ by formic acid and palladium. The solid-phase synthesis of 2,3,5-trisubstituted furans from 1,4-diketones was also reported <03SL711>. 

The Noyori asymmetric transfer hydrogenation was utilized in the synthesis of the chiral 1,2,3,4-tetrahydroisoquinolines by R.A. Sheldon et al. These compounds are important intermediates in the Rice and Beyerman routes to morphine. The "Rice imine" was exposed to a series of chiral Ru " complexes, which was prepared from r -arene-Ru " chloride dimeric complexes and A/-sulfonated 1,2-diphenylethylenediamines along with the azeotropic mixture of HCOOH/NEts. With the best catalyst the desired tetrahydroisoquinoline was isolated in 73% yield and the enantiomeric excess was 99%. 

Schoemaker and Speckamp (8) have reported the quantitative conversion of hydroxy-lactam (n=l) (HCOOH, 18 h, r.t.) into the spirocyclic lactam ester (n=l). The other possible spiroisomer (n=l) was not formed. Hydroxy-lactam 26 (n=2) gave spiroisomer (n=2), albeit in lower yield, under similar conditions. The same authors (9) have also reported the successful cyclization of hydroxy-lactam W into spirolactam Analogous results were obtained by Evans and Thomas (10) who found that the cycliza-tion of a 9 1 mixture of enamides and in anhydrous formic acid gave the spirocompound 30. This compound is a key intermediate in Kishi s total synthesis of perhydrohistrionicotoxin (11, 12). 

SCHEME 7. Synthesis otturan tatty acid [21J. Keagents (i) lithium acetylide, tetrahy-drofuran (THF) (ii) H2O, HCOOH (iii) heptynyllithium (iv) aqueous f-butyl hydroperoxide, catalytic VO(acac)2 (v) HgCl2, H2SO4 (vi) pyridinium dichromate. 

It has been found that in aqueous solution HCl and trifluoroacetic acid are superior to CH3COOH, HCOOH, CSA, and TCA. Current studies of this reaction focus on the diastereoselective and enantioselective synthesis of tetrahydroisoquinolines via chirality transfer from the auxiliary group of either the arylethylamine or the carbonyl component,or the application of chiral Lewis acid. °° ... 

Fabio H. B. Lima was bom in Brazil in 1978. He graduated in Chemistry at University of Sao Paulo, Sao Carlos, in 2001. He obtained his Ph.D. in Physical Chemistry in the same institution, in 2006, with a stage at the Brookhaven National Laboratory. He spent 12 months as a postdoctoral fellow at the Chemistry Institute of Sao Carlos (IQSC) between 2006 and 2008. He is currently interested in synthesis and electrocatalysis for reactions involved in electrochemical energy conversion devices such as regenerative fuel cells (H2/O2 and HCOOH/CO2), rechargeable metal-air batteries, direct hydrazine, borohydride and ethanol fuel cells. Publication of scientific research includes 36 articles in journals, 3 chapters in books and more than 50 scientific summaries in collective books and proceedings. 

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