Formation of diethyl 2-amino-1-cyclopentenylphosphonates: a simple synthesis with a unique mechanism.
Reaction of diethyl 5-chloro-1-pentynylphosphonate with primary and secondary amines produces novel 2-amino-1-cyclopentenylphosphonates, 1, in excellent isolated yields (79-88%). Calculations supported by experimental facts point to a two-step mechanism: an initial amine addition to give a zwitterionic intermediate followed by cyclization and proton transfer. Calculations rule out the formation of an enamine as an intermediate.
Al Quntar
Abed Al Aziz
AA
Department of Medicinal Chemistry and Natural Products, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
Srivastava
Hemant Kumar
HK
Srebnik
Morris
M
Melman
Artem
A
Ta-Shma
Rachel
R
Shurki
Avital
A
D000588:Amines / Q000737:chemistry*; D003517:Cyclopentanes / Q000737:chemistry*; D005030:Ethylenes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D063065:Organophosphonates / Q000138:chemical synthesis / Q000737:chemistry*
D000588:Amines; D003517:Cyclopentanes; D005030:Ethylenes; D063065:Organophosphonates; C036216:ethylene