PyBOP® and PyBroP: Two reagents for the difficult coupling of the α,α-dialkyl amino acid, Aib.
摘要:
The difficult coupling of alpha-aminoisobutyric acid (Aib) was carried out using PyBOP(R) and PyBroP in a comparative study with BOP and BroP. These reagents gave good results under simple conditions (one pot, r.t., 1 h). Coded amino acids could be coupled with Aib using PyBOP under standard conditions of peptide synthesis without racemization whereas the coupling of two Aib residues required PyBroP/DMAP. A fragment containing an Aib C-terminal could be coupled without epimerization of the penultimate residue.
PyBOP® and PyBroP: Two reagents for the difficult coupling of the α,α-dialkyl amino acid, Aib.
摘要:
The difficult coupling of alpha-aminoisobutyric acid (Aib) was carried out using PyBOP(R) and PyBroP in a comparative study with BOP and BroP. These reagents gave good results under simple conditions (one pot, r.t., 1 h). Coded amino acids could be coupled with Aib using PyBOP under standard conditions of peptide synthesis without racemization whereas the coupling of two Aib residues required PyBroP/DMAP. A fragment containing an Aib C-terminal could be coupled without epimerization of the penultimate residue.
Asymmetric Synthesis of β,β-Disubstituted Alanines via a Sequential C(sp2)–C(sp3) Cross-Coupling–Hydrogenation Strategy
作者:David A. Petrone、Jonathan Maturano、James Herbort、Erin E. Plasek、J. Mayeli Vivaldo-Nikitovic、David Sarlah
DOI:10.1021/acs.orglett.4c02376
日期:2024.7.26
allows access to a diverse array of valuable β,β-disubstituted alanine derivatives. This synthesis exhibits broad functional group tolerance, and permits efficient access to β-aryl-β-alkyl, and the more rarely reported β,β-dialkyl Ala derivatives with high yield and excellent enantioselectivity. This transformation has been exhibited on decagram quantity, and can be used to generate Fmoc aminoacid derivatives