121671-76-9Relevant articles and documents
Iodine in dichloromethane - A simple method for selective cleavage of prenyl ethers
Vatèle
, p. 1989 - 1991 (2001)
Treatment of prenyl (Pre) ethers of simple alcohols, carbohydrates, steroids, with I2 in CH2Cl2 in the presence of 3? molecular sieves, constitutes an effective method for their deprotection. This method tolerates other etheral functionalities such as acetals, allyl, t-butyldiphenylsilyl or benzyl groups as well as base labile groups such as acetates. This method applied to a prenyl aryl ether gave rise to a 2,2-dimethylchroman derivative in an acceptable yield.
Bismuth(III) chloride catalyzed efficient and selective cleavage of trityl ethers
Sabitha, Gowravaram,Reddy, E. Venkata,Swapna,Reddy, N. Mallikarjun,Yadav
, p. 1276 - 1278 (2004)
A highly selective and efficient protocol has been developed for detritylation using 5 mol% BiCl3 in acetonitrile. The cleavage proceeds at room temperature in high yields and the conditions are mild enough to tolerate a variety of acid-base sensitive functional groups.
An efficient and chemoselective cleavage of prenyl ethers with DDQ
Vatéle, Jean-Michel
, p. 507 - 509 (2002)
The prenyl (Pre) protecting group tor hydroxyl functions is readily removed at room temperature with DDQ in dichloromethane-water (9:1). The reaction conditions are compatible with the presence of other ethereal functionalities such as acetonides, allyl, benzyl, TBS, TBDPS groups. We have also shown that Sdeprotection of prenyl ethers using a catalytic amount of DDQ in the presence of 3 equivalents of Mn(OAc)3 is a good alternative for the use of a stoichiometric amount of DDQ, albeit the reaction time being longer.
A mild and selective cleavage of tert-butyldimethylsilyl ethers by indium(III) chloride
Yadav,Subba Reddy,Madan
, p. 853 - 854 (2000)
Alkyl tert-butyldimethylsilyl ethers are selectively deprotected to the corresponding alcohols in high yields for the first time by indium(III) chloride in refiuxing aqueous acetonitrile. Several functional groups like OBn, Boc, CBz, OBz, O-allyl, OTBDPS, OAc, OMe, ethers, esters and olefins present in the substrate are unaffected.
Deprotection of silyl ethers using ZnBr2 and H2O in CH2Cl2
Crouch, R.David,Polizzi, Joanna M.,Cleiman, Rebecca A.,Yi, Jihae,Romany, Candice A.
, p. 7151 - 7153 (2002)
TES- and TBS-protected alcohols undergo deprotection upon treatment with excess ZnBr2 and water in CH2Cl2 at 44-50°C. TIPS-protected alcohols also undergo deprotection but at slower rates. TBDPS-protected alcohols and silyl-protected phenols are unreactive under these conditions, allowing for selective deprotection of differentially-protected bis-silyl ethers.
Rapid, acid-mediated deprotection of silyl ethers using microwave heating
Crouch,Williams, Anna
, p. 959 - 964 (2006)
Microwave heating of triethylsilyl (TES)- and tert-butyldimethylsilyl (TBS)-protected 1° and 2° alcohols in a mixture of equal parts acetic acid, tetrahydrofuran (THF), and water allows deprotection in as little as 5 min. tert-butyldiphenylsilyl (TBDPS)- and triisopropylsilyl (TIPS)-protected alcohols and silyl-protected phenols are stable in these conditions. Thus, selective deprotection of TES- and TBS-protected alcohols in the presence of TIPS or TBDPS ethers is possible. Similarly, alkyl silyl ethers can be deprotected in the presence of aryl silyl ethers. Copyright Taylor & Francis Group, LLC.
Synthesis of the tetracyclic ABCE ring subunit I, bearing the 13- membered azacycle, of manzamine A
Li, Shouming,Yamamura, Shosuke
, p. 8691 - 8710 (1998)
The tetracyclic ABCE ring, which bears the crucial 13-membered azacycle, of manzamine A has been synthesized through the corresponding bicyclic BC ring subunit as a promising synthetic intermediate.
A convenient biphasic process for the monosilylation of symmetrical 1,n- primary diols
Yu, Chengzhi,Liu, Bin,Hu, Longqin
, p. 4281 - 4285 (2000)
A simple and mild biphasic process was developed for the selective protection of one of two chemically equivalent primary hydroxyl groups in 1,n-diols using t-butyldiphenyl silyl chloride in diisopropyl ethyl amine and dimethyl formamide. (C) 2000 Elsevier Science Ltd.
Synthesis of AD-Dihydrodipyrrins Equipped with Latent Substituents of Native Chlorophylls and Bacteriochlorophylls
Wang, Pengzhi,Lindsey, Jonathan S.
, p. 11794 - 11811 (2021/08/24)
Native chlorophylls and bacteriochlorophylls share a common trans-substituted pyrroline ring D (17-propionic acid, 18-methyl), whereas diversity occurs in ring A particularly at the 3-position. Two dihydrodipyrrins equipped with native-like D-ring substit
NOVEL IMIDAZO-PYRAZINE DERIVATIVES
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Page/Page column 45; 115-116, (2021/12/31)
The invention provides novel imidazo-pyrazine derivatives having the general formula (I), and pharmaceutically acceptable salts thereof, wherein X, m, n, and R1to R3 are as described herein: formula (I). Further provided are pharmace
