Novel Protecting Groups for Oligosaccharides Synthesis.

Carbohydrates contain numerous hydroxyl groups and sometimes amine functionalities which lead to a variety of complex structures.  In order to discriminate each hydroxyl groups for the synthesis of complex oligosaccharides, protecting group manipulations are essential.  Although the primary role of a protecting group is to temporarily mask a particular hydroxyl/amino group group, it plays a greater role in tuning the reactivity of coupling partners as well as regioselectivity and stereoselectivity of glycosylations.  Several protecting groups offer anchimeric assistance in glycosylation.  They also alter the solubility of substrates and thereby influence the reaction outcome.  Since oligosaccharides comprise branched structures, the glycosyl donors and acceptors needs to be protected with orthogonal protected groups that can be selectively removed one at a time without affecting other groups.  The mini-review is therefore intended to provide a discussion on the new protecting groups for amino and hydroxyl groups, which have been introduced over last ten years in the field of carbohydrate synthesis.  These protecting groups are also useful for synthesizing non-carbohydrate target molecules as well.

[1]  P. Seeberger,et al.  Synthesis of photolabile protecting group (PPG) protected uronic acid building blocks: applications in carbohydrate synthesis with the assistance of a continuous flow photoreactor , 2019, Organic Chemistry Frontiers.

[2]  R. Schmidt,et al.  Dual-Participation Protecting Group Solves the Anomeric Stereocontrol Problems in Glycosylation Reactions. , 2019, Organic letters.

[3]  C. Hametner,et al.  2-O-Benzyloxycarbonyl protected glycosyl donors: a revival of carbonate-mediated anchimeric assistance for diastereoselective glycosylation. , 2019, Chemical communications.

[4]  R. Schmidt,et al.  The 2,2-Dimethyl-2-(ortho-nitrophenyl)acetyl (DMNPA) Group: A Novel Protecting Group in Carbohydrate Chemistry. , 2019, Organic letters.

[5]  K. Murasawa,et al.  p-Methylbenzyl Group: Oxidative Removal and Orthogonal Alcohol Deprotection. , 2019, Organic letters.

[6]  H. Ishida,et al.  p- tert-Butyl Groups Improve the Utility of Aromatic Protecting Groups in Carbohydrate Synthesis. , 2019, Organic letters.

[7]  R. Vishwakarma,et al.  Introducing Oxo-Phenylacetyl (OPAc) as a Protecting Group for Carbohydrates. , 2019, The Journal of organic chemistry.

[8]  T. Lecourt,et al.  Regio- and Chemoselective Deprotection of Primary Acetates by Zirconium Hydrides. , 2019, Organic letters.

[9]  T. Boltje,et al.  α-Selective Glycosylation with β-Glycosyl Sulfonium Ions Prepared via Intramolecular Alkylation , 2019, The Journal of organic chemistry.

[10]  T. Oishi,et al.  1,2- trans Glycosylation via Neighboring Group Participation of 2- O-Alkoxymethyl Groups: Application to One-Pot Oligosaccharide Synthesis. , 2019, Organic letters.

[11]  C. Hametner,et al.  (2-Benzyloxyphenyl)acetyl (BnPAc): A Participating Relay Protecting Group for Diastereoselective Glycosylation and the Synthesis of 1,2-trans Glycosyl Esters , 2018, Synlett.

[12]  Suvarn S. Kulkarni,et al.  Chemical Synthesis of Rare, Deoxy-Amino Sugars Containing Bacterial Glycoconjugates as Potential Vaccine Candidates , 2018, Molecules.

[13]  Yukishige Ito,et al.  Bimodal Glycosyl Donors Protected by 2- O-( ortho-Tosylamido)benzyl Group. , 2018, Organic letters.

[14]  Narayana Murthy Sabbavarapu,et al.  "One-Pot" Protection, Glycosylation, and Protection-Glycosylation Strategies of Carbohydrates. , 2018, Chemical reviews.

[15]  You-Yu Lin,et al.  2- O- N-Benzylcarbamoyl as a Protecting Group To Promote β-Selective Glycosylation and Its Applications in the Stereoselective Synthesis of Oligosaccharides. , 2018, The Journal of organic chemistry.

[16]  D. Crich,et al.  Hydrogenolytic cleavage of naphthylmethyl ethers in the presence of sulfides. , 2017, Carbohydrate research.

[17]  T. Oishi,et al.  1-Naphthylmethyl and 1-naphthylmethoxymethyl protecting groups: New members of the benzyl- and benzyloxymethyl-type family , 2017 .

[18]  Clay S. Bennett,et al.  Mild Method for 2-Naphthylmethyl Ether Protecting Group Removal Using a Combination of 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and β-Pinene , 2017, The Journal of organic chemistry.

[19]  Suvarn S. Kulkarni.  Regioselective, One‐Pot Functionalization of Carbohydrates , 2017 .

[20]  H. Overkleeft,et al.  The Cyanopivaloyl Ester: A Protecting Group in the Assembly of Oligorhamnans , 2016 .

[21]  K. Ágoston,et al.  Orthogonal protecting group strategies in carbohydrate chemistry , 2016 .

[22]  Y. Niu,et al.  3-Butenyloxycarbonyl as a new hydroxyl protecting group in carbohydrate synthesis , 2016 .

[23]  A. Fairbanks,et al.  Protecting Group Dependence of Stereochemical Outcome of Glycosylation of 2‐O‐(Thiophen‐2‐yl)methyl Ether Protected Glycosyl Donors , 2016 .

[24]  T. Lowary,et al.  Development of an Orthogonal Protection Strategy for the Synthesis of Mycobacterial Arabinomannan Fragments. , 2015, The Journal of organic chemistry.

[25]  D. Filippov,et al.  Chemoselective Cleavage of p-Methoxybenzyl and 2-Naphthylmethyl Ethers Using a Catalytic Amount of HCl in Hexafluoro-2-propanol. , 2015, The Journal of organic chemistry.

[26]  T. Oishi,et al.  2-Naphthylmethoxymethyl as a Mildly Introducible and Oxidatively Removable Benzyloxymethyl-Type Protecting Group. , 2015, Organic letters.

[27]  N. Bovin,et al.  New protecting groups in the synthesis of oligosaccharides , 2015, Russian Chemical Bulletin.

[28]  K. K. Mong,et al.  C6 picoloyl protection: a remote stereodirecting group for 2-deoxy-β-glycoside formation. , 2015, Chemical communications.

[29]  Xue‐Wei Liu,et al.  The intriguing dual-directing effect of 2-cyanobenzyl ether for a highly stereospecific glycosylation reaction , 2014, Nature Communications.

[30]  Suvarn S. Kulkarni,et al.  Recent advances in synthesis of bacterial rare sugar building blocks and their applications. , 2014, Natural product reports.

[31]  Xinyu Liu,et al.  Tunable acid-sensitive ester protecting groups in oligosaccharide synthesis. , 2014, Chemical communications.

[32]  K. K. Mong,et al.  Tuning reactivity of glycosyl imidinium intermediate for 2-azido-2-deoxyglycosyl donors in α-glycosidic bond formation. , 2013, Organic letters.

[33]  Suvarn S. Kulkarni,et al.  Synthesis of orthogonally protected bacterial, rare-sugar and D-glycosamine building blocks , 2013, Nature Protocols.

[34]  Jin-Song Yang,et al.  β-Arabinofuranosylation using 5-O-(2-quinolinecarbonyl) substituted ethyl thioglycoside donors. , 2013, Organic letters.

[35]  J. Młynarski,et al.  Application of the 2‐Nitrobenzyl Group in Glycosylation Reactions: A Valuable Example of an Arming Participating Group , 2013 .

[36]  G. Painter,et al.  The dimethoxyphenylbenzyl protecting group: an alternative to the p-methoxybenzyl group for protection of carbohydrates. , 2013, The Journal of organic chemistry.

[37]  H. Overkleeft,et al.  2,2-Dimethyl-4-(4-methoxy-phenoxy) butanoate and 2,2-dimethyl-4-azido butanoate: two new pivaloate-ester-like protecting groups. , 2013, Organic letters.

[38]  Zhitao Li,et al.  Study of the stereoselectivity of 2-azido-2-deoxyglucosyl donors: protecting group effects. , 2013, Organic & biomolecular chemistry.

[39]  R. Givens,et al.  Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy , 2012, Chemical reviews.

[40]  J. P. Yasomanee,et al.  Effect of remote picolinyl and picoloyl substituents on the stereoselectivity of chemical glycosylation. , 2012, Journal of the American Chemical Society.

[41]  S. Antus,et al.  Selective removal of the (2-naphthyl)methyl protecting group in the presence of p-methoxybenzyl group by catalytic hydrogenation , 2012 .

[42]  Xinyu Liu,et al.  New insight on 2-naphthylmethyl (NAP) ether as a protecting group in carbohydrate synthesis: a divergent approach towards a high-mannose type oligosaccharide library. , 2011, Chemical communications.

[43]  H. Overkleeft,et al.  Novel protecting groups in carbohydrate chemistry , 2011 .

[44]  Jian Guo,et al.  Protecting Groups in Carbohydrate Chemistry: Influence on Stereoselectivity of Glycosylations , 2010, Molecules.

[45]  Hien M. Nguyen,et al.  Nickel-catalyzed stereoselective glycosylation with C(2)-N-substituted benzylidene D-glucosamine and galactosamine trichloroacetimidates for the formation of 1,2-cis-2-amino glycosides. Applications to the synthesis of heparin disaccharides, GPI anchor pseudodisaccharides, and α-GalNAc. , 2010, Journal of the American Chemical Society.

[46]  P. Fügedi,et al.  (2-Nitrophenyl)acetyl: a new, selectively removable hydroxyl protecting group. , 2010, Organic letters.

[47]  Andrew G. Leach,et al.  Stereoselective glycosylation using oxathiane glycosyl donors. , 2009, Chemical communications.

[48]  P. Seeberger,et al.  Carbohydrates: A Frontier in Medicinal Chemistry , 2009 .

[49]  Hien M. Nguyen,et al.  Nickel-catalyzed stereoselective formation of alpha-2-deoxy-2-amino glycosides. , 2009, Journal of the American Chemical Society.

[50]  A. Fairbanks,et al.  Stereoselective synthesis of α-glucosides by neighbouring group participation via an intermediate thiophenium ion , 2009 .

[51]  Biao Yu,et al.  N-Dimethylphosphoryl-protection in the efficient synthesis of glucosamine-containing oligosaccharides with alternate N-acyl substitutions , 2007 .

[52]  Biao Yu,et al.  N-Dimethylphosphoryl-protected glucosamine trichloroacetimidate as an effective glycosylation donor , 2007 .

[53]  G. Boons,et al.  Stereoselective glycosylations of 2-azido-2-deoxy-glucosides using intermediate sulfonium ions. , 2007, Organic letters.

[54]  G. Boons,et al.  A general strategy for stereoselective glycosylations. , 2005, Journal of the American Chemical Society.

[55]  C. Bertozzi,et al.  Glycans in cancer and inflammation — potential for therapeutics and diagnostics , 2005, Nature Reviews Drug Discovery.

[56]  S. Hung,et al.  Neighboring group participation of 9-anthracenylmethyl group in glycosylation: preparation of unusual C-glycosides. , 2005, The Journal of organic chemistry.

[57]  P. Seeberger,et al.  A Suzuki-Miyaura coupling mediated deprotection as key to the synthesis of a fully lipidated malarial GPI disaccharide. , 2004, Chemical communications.

[58]  S. Hakomori,et al.  Glycosylation defining cancer malignancy: New wine in an old bottle , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[59]  J. Ning,et al.  Pure α-linked products can be obtained in high yields in glycosylation with glucosyl trichloroacetimidate donors with a C2 ester capable of neighboring group participation , 2002 .

[60]  V. Dudkin,et al.  Why are the hydroxy groups of partially protected N-acetylglucosamine derivatives such poor glycosyl acceptors, and what can be done about it? A comparative study of the reactivity of N-acetyl-, N-phthalimido-, and 2-azido-2-deoxy-glucosamine derivatives in glycosylation. 2-Picolinyl ethers as react , 2001, Journal of the American Chemical Society.

[61]  T. Ziegler,et al.  Prearranged glycosides. Part 14: Intramolecular glycosylation of non-symmetrically tethered glycosides , 2001 .

[62]  P. Kocieňski,et al.  Protecting groups , 1999 .

[63]  T. Harada,et al.  Synthesis of An Elicitor-Active Hexaglucoside Analog by a One-Pot, Two-Step Glycosidation Procedure , 1994 .

[64]  S. Hakomori.  Carbohydrate-carbohydrate interaction as an initial step in cell recognition , 1991 .

[65]  J. G. Buchanan,et al.  623. Synthesis of 4-O-?-D-glucosaminyl-D-ribitol and 4-O-?-D-glucosaminyl-D-ribitol, degradation products of the ribitol teichoic acid from Staphylococcus aureus H , 1963 .