Novel and facile solution-phase synthesis of 2,5-diketopiperazines and O-glycosylated analogs
摘要:
This work describes the synthesis in Solution of a series of related diketopiperazines with potential biological activities: cyclo(L-Pro-L-Ser), cyclo(L-Phe-L-Ser), cyclo(D-Phe-L-Ser) and the corresponding glycosylated analogs of the latter, cyclo[D-Phe-L-Ser(alpha GlcNAc)] and cyclo[D-Phe-L-Ser(beta GlcNAc)]. The synthetic approach involved coupling reactions of -OH or O-glycosylated serine benzyl esters with NFmoc-protected amino acids (Pro or Phe), followed by one-pot deprotection-cyclization reaction in the presence of 20% piperidine in DMF. (C) 2009 Elsevier Ltd. All rights reserved.
Use of Catalytic Fluoride under Neutral Conditions for Cleaving Silicon–Oxygen Bonds
摘要:
This Article describes the development of conditions for cleaving silicon oxygen bonds using catalytic quantities of fluoride at neutral pH in mixed organic aqueous solutions that contain buffer. A variety of silicon protecting groups can be removed under these conditions, which show tolerance for acid- and base-sensitive groups. A modified procedure also is presented using catalytic fluoride in anhydrous dimethyl sulfoxide-methanol, which generates primarily volatile silicon byproducts.
Novel and facile solution-phase synthesis of 2,5-diketopiperazines and O-glycosylated analogs
作者:Vanessa L. Campo、Maristela B. Martins、Carlos H.T.P. da Silva、Ivone Carvalho
DOI:10.1016/j.tet.2009.04.069
日期:2009.7
This work describes the synthesis in Solution of a series of related diketopiperazines with potential biological activities: cyclo(L-Pro-L-Ser), cyclo(L-Phe-L-Ser), cyclo(D-Phe-L-Ser) and the corresponding glycosylated analogs of the latter, cyclo[D-Phe-L-Ser(alpha GlcNAc)] and cyclo[D-Phe-L-Ser(beta GlcNAc)]. The synthetic approach involved coupling reactions of -OH or O-glycosylated serine benzyl esters with NFmoc-protected amino acids (Pro or Phe), followed by one-pot deprotection-cyclization reaction in the presence of 20% piperidine in DMF. (C) 2009 Elsevier Ltd. All rights reserved.
Use of Catalytic Fluoride under Neutral Conditions for Cleaving Silicon–Oxygen Bonds
作者:Anthony M. DiLauro、Wanji Seo、Scott T. Phillips
DOI:10.1021/jo200848j
日期:2011.9.16
This Article describes the development of conditions for cleaving silicon oxygen bonds using catalytic quantities of fluoride at neutral pH in mixed organic aqueous solutions that contain buffer. A variety of silicon protecting groups can be removed under these conditions, which show tolerance for acid- and base-sensitive groups. A modified procedure also is presented using catalytic fluoride in anhydrous dimethyl sulfoxide-methanol, which generates primarily volatile silicon byproducts.