Table 6.

Commercially available building blocking blocks for introduction of principle PTMs

PTM	Introduction	Comments	Reference
Phosphorylation Ser/Thr
	Fmoc‐Ser(PO(OBzl)OH)‐OH 17	Best coupled using imminium‐based reagents 135	Wakamiya et al., 1994 136
Tyr	Fmoc‐Thr(PO(OBzl)OH)‐OH 18	Best coupled using imminium‐based reagents 135	White and Beythien, 1996 137
	Fmoc‐Tyr(PO(OMe)2)‐OH 19	Compatible with all coupling methods; monodemethylated by piperidine; requires TMSBr/TFA for side‐chain deprotection	Kitas et al., 1989 138
	Fmoc‐Tyr(PO(OBzl)OH)‐OH 20	Best coupled using imminium‐based reagents 154	White and Beythien, 1996 137
	Fmoc‐Tyr(PO(OBzl)2)‐OH 21	Compatible with all coupling methods; monodebenzylated by piperidine	Perich and Reynolds, 1991 139
	Fmoc‐Tyr(PO3H2)‐OH 22	Best coupled using imminium‐based reagents; issues with pyrophosphate formation 143	Ottinger et al., 1993 140
	Fmoc‐Tyr(PO(NMe2)2)‐OH 23	Compatible with all coupling methods; deprotected with TFA/water (9 : 1)	Chao et al., 1995 141
	Fmoc‐Tyr(PO(OMDPSE)2)‐OH 24	Compatible with all coupling methods; MDPSE groups removed with TFA	Chao et al., 1994 142
	Fmoc‐Ppa(Bzl)‐OH 25	Best coupled using imminium‐based reagents	Chauhan et al., 2007 143
	Fmoc‐Pmp‐OH 26	Best introduced with HATU/DIPEA coupling	Marseigne et al., 1988 144
	Fmoc‐F2Pmp‐OH 27	Best introduced with HATU/DIPEA coupling	Gordeev et al., 1994 145
Sulfation Tyr
	Fmoc‐Tyr(SO3nP)‐OH 28	Neopentyl ester is stable to TFA; cleaved with sodium azide/DMSO or aq. ammonium acetate	Simpson and Widlanski, 2006 [146, 147]
	Fmoc‐Tyr(SO3DCV)‐OH 29	DCV ester stable to TFA; DCV cleaved by Zn/AcOH reduction	Ali and Taylor, 2009 148, 149
Methylation Arg
	Fmoc‐Arg(Me,Pbf)‐OH 30	For introduction of monomethyl arginine	White, 2006 150
	Fmoc‐ADMA(Pbf)‐OH 31	For introduction of asymmetric dimethylarginine	White et al., 2006 150
	Fmoc‐SDMA(Boc2)‐ONa 32	For introduction of symmetric dimethylarginine	White et al., 2006 150
Methylation Lys
	Fmoc‐Lys(Me,Boc)‐OH 33	For introduction of monomethyl lysine
	Fmoc‐Lys(Me2)‐OH 34	For introduction of dimethyl lysine, basic side chain can promote Fmoc loss and double insertions during synthesis 151
	Fmoc‐Lys(Me3Cl)‐OH 35	For introduction of trimethyl lysine
Citrullation
	Fmoc‐citrulline‐OH 36	For introduction of citrullation
Glycosylation Asn
	Fmoc‐Asn(β‐d‐GlcNAc(Ac)3)‐OH 37	Building block for introduction of monosaccharide fragment of N‐linked glycoproteins	Meldal and Bock, 1990 152
	Fmoc‐Asn(β‐d‐GlcNAc(Ac)3‐(1‐4)‐β‐d‐GlcNAc(Ac)2)‐OH 38	Building block for introduction of chitobiose fragment of N‐linked glycoproteins	Meinjohanns et al., 1998 153
Glycosylation Ser (R = H)/Thr (R = Me)
	Fmoc‐Ser/Thr(α‐d‐GlnNAc(Ac)3)‐OH 39	Building block for introduction of Tn antigen oligosaccharide fragment	Paulsen and Adermann, 1989 154
	Fmoc‐Ser/Thr(β‐d‐Gal(Ac)4‐(1‐3) α‐d‐GlnNAc(Ac)2)‐OH 40 TF antigen	Building block for introduction of TF antigen oligosaccharide fragment	Irazoqui et al., 1999 155
	Fmoc‐Ser/Thr(sialylOMe(Ac)4‐(1‐6)‐α‐d‐GlnNAc(Ac)2)‐OH 41 STn antigen	Building block for introduction of STn antigen oligosaccharide fragment	Liebe and Kunz, 1997 156
	Fmoc‐Ser/Thr(sialylOMe(Ac)4‐(1‐3)‐β‐d‐Gal(Ac)3‐(1‐3) α‐d‐GlnNAc(Ac)2)‐OH 42 STF antigen	Building block for introduction of STn antigen oligosaccharide fragment	Komba et al., 1999 157
	Fmoc‐Ser/Thr(β‐d‐GlcNAc(Ac)3)‐OH 43	Building block for introduction of β‐GlcNAc modification; building blocks tend to racemise 158	Arsequell et al., 1994 159