24469-50-9Relevant articles and documents
Synthesis of boronophenylalanine-like aza-amino acids for boron-containing azapeptide precursors
Miyata, Kota,Narita, Airi,Fujisawa, Ryota,Roppongi, Makoto,Ito, Satoshi,Shingo, Tamesue,Oba, Toru
, (2020)
Aza-amino acids and an azapeptide with a boron-containing substituent were developed for the first time. We synthesized p-boronophenylalanine (BPA)-like aza-amino acid (aza-BPA) and its analogs in which the α-carbon of the peptide is replaced by nitrogen and the boronate ester is situated at the ortho, meta, or para position of the phenyl group. The N- and C-terminals of aza-BPA were linked to α-amino acids to afford an α/aza/α-tripeptide. These compounds are expected to be used in boron neutron capture therapy, chemotherapy, and synthesis of functional materials.
Mn(III)-mediated phosphinoylation of aldehyde hydrazones: Direct “one-pot” synthesis of α-iminophosphine oxides from aldehydes
Bian, Xue-Wei,Zhang, Ling,Shoberu, Adedamola,Zou, Jian-Ping
supporting information, (2021/04/02)
A “one-pot” strategy for the straightforward Mn(III)-mediated phosphinoylation of aldehyde hydrazones with diphenylphosphine oxide to furnish α-iminophosphine oxides is described. This mild and practical method allows the direct use of aldehydes as substrates in one pot to generate the hydrazones, which are then engaged “in situ” by the phosphorus reagent in the presence of Mn(OAc)3 oxidant. Thus, the requisite isolation of the hydrazones is not needed in this operation. Conducted mechanistic experiments implicate a pathway involving phosphorus-centered radicals.
Regiocontrolled and Stereoselective Syntheses of Tetrahydrophthalazine Derivatives using Radical Cyclizations
Zhang, Wei,Mo, Jia Yi,He, Weiying,Kennepohl, Pierre,Sammis, Glenn M.
supporting information, p. 976 - 980 (2019/01/04)
Tetrahydrophthalazine derivatives have found important applications in pharmaceutical research, but existing synthetic methods are unable to access them regio- and stereoselectively. Here, a new approach is presented that addresses these challenges by utilizing a 6-endo-trig radical cyclization in the key step. The desired tetrahydrophthalazines can be accessed in high yields (55–98 %) and high diastereoselectivities for the trans-product (>95:5) starting either from readily accessible hydrazones, or from the corresponding aldehydes and substituted Boc-hydrazides in a one-pot process. The synthetic versatility of the tetrahydrophthalazine core was demonstrated by its straightforward conversion to dihydro-phthalazines, phthalazines, or pyrazolo dione derivatives. Furthermore, the N?N bond was reduced to afford a new route to 1,4-diamines.
