BOP reagent
{{chembox
| Watchedfields = changed
| verifiedrevid = 408852615
| ImageFile = BOP reagent.svg
| ImageSize =
| IUPACName = ((1H-Benzo[d][1,2,3]triazol-1-yl)oxy)tris(dimethylamino)phosphonium hexafluorophosphate(V)
| OtherNames = Castro's reagent
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 56602-33-6
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = LBD3UE345W
| PubChem = 151348
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 133386
| SMILES = F[P-](F)(F)(F)(F)F.n1nn(O[P+](N(C)C)(N(C)C)N(C)C)c2ccccc12
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI =1S/C12H22N6OP.F6P/c1-15(2)20(16(3)4,17(5)6)19-18-12-10-8-7-9-11(12)13-14-18;1-7(2,3,4,5)6/h7-10H,1-6H3;/q+1;-1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = MGEVGECQZUIPSV-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| Formula = C12H22F6N6OP2
| MolarMass = 442.287 g/mol
| Appearance = White crystalline powder
| Density =
| MeltingPtC = 136 to 140
| MeltingPt_notes =
| BoilingPt =
| Solubility = Partially soluble in cold water reacts (decomposes)
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
}}
}}
{{Technical|date=January 2021}}
BOP (benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate) is a reagent commonly used for the synthesis of amides from carboxylic acids and amines in peptide synthesis.{{Cite web|url=https://www.sigmaaldrich.com/catalog/product/aldrich/226084|title=(Benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate 226084|website=BOP Reagent|access-date=2020-02-11}}{{Cite journal |last1=Mansour |first1=Tarek S. |last2=Bardhan |first2=Sujata |last3=Wan |first3=Zhao-Kui |date=2010 |title=Phosphonium- and Benzotriazolyloxy-Mediated Bond-Forming Reactions and Their Synthetic Applications |url=http://www.thieme-connect.de/DOI/DOI?10.1055/s-0029-1219820 |journal=Synlett |language=en |volume=2010 |issue=8 |pages=1143–1169 |doi=10.1055/s-0029-1219820 |issn=0936-5214}} It can be prepared from 1-hydroxybenzotriazole and a chlorophosphonium reagent under basic conditions.{{Cite journal |last1=Hoffmann |first1=Frank |last2=Jäger |first2=Lothar |last3=Griehl |first3=Carola |date=2003-02-01 |title=Synthesis and Chemical Constitution of Diphenoxyphosphoryl Derivatives and Phosphonium Salts as Coupling Reagents for Peptide Segment Condensation |url=https://www.tandfonline.com/doi/full/10.1080/10426500307942 |journal=Phosphorus, Sulfur, and Silicon and the Related Elements |language=en |volume=178 |issue=2 |pages=299–309 |doi=10.1080/10426500307942 |issn=1042-6507}} This reagent has advantages in peptide synthesis since it avoids side reactions like the dehydration of asparagine or glutamine redisues.{{Cite journal |last1=Prasad |first1=KVSRG |last2=Bharathi |first2=K |last3=Haseena |first3=Banu B |date=2011 |title=Applications of Peptide Coupling Reagents- An Update |url=https://globalresearchonline.net/journalcontents/volume8issue1/Article-021.pdf |journal=International Journal of Pharmaceutical Sciences Review and Research |volume=8 |issue=1 |pages=108–119}} BOP has used for the synthesis of esters from the carboxylic acids and alcohols.{{Cite journal |last1=Kim |first1=Moon H. |last2=Patel |first2=Dinesh V. |date=1994-08-01 |title="BOP" as a reagent for mild and efficient preparation of esters |url=https://www.sciencedirect.com/science/article/pii/S0040403900772571 |journal=Tetrahedron Letters |volume=35 |issue=31 |pages=5603–5606 |doi=10.1016/S0040-4039(00)77257-1 |issn=0040-4039}} BOP has also been used in the reduction of carboxylic acids to primary alcohols with sodium borohydride (NaBH4).{{Cite journal |last=McGeary |first=Ross P. |date=1998 |title=Facile and chemoselective reduction of carboxylic acids to alcohols using BOP reagent and sodium borohydride |journal=Tetrahedron Letters |language=en |volume=39 |issue=20 |pages=3319–3322 |doi=10.1016/S0040-4039(98)00480-8 |issn=0040-4039}} Its use raises safety concerns since the carcinogenic compound HMPA is produced as a stoichiometric by-product.