Phospha-Michael addition reaction of maleimides employing N-heterocyclic phosphine-thiourea as a phosphonylation reagent: synthesis of 1-aryl-2,5-dioxopyrrolidine-3-yl-phosphonate derivatives.
N-Heterocyclic phosphine (NHP)-thiourea as a novel phosphonylation reagent has been successfully applied for the phospha-Michael reaction of maleimides under catalyst and additive free reaction conditions. This methodology enables desymmetrization of a variety of maleimide derivatives to provide 1-aryl-2,5-dioxopyrrolidine-3-yl-phosphonates in up to 92% yield. Synthetic manipulation of this Michael adduct afforded an ethylphosphonate and a phosphino lactam. Furthermore, a scale-up experiment for its practical usage as a versatile precursor in organic synthesis was readily demonstrated.
Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154-4003, USA. junyong.kang@unlv.edu.
Nagaraju
N
Molleti
Chad
C
Bjornberg
Jun Yong
JY
Kang
D060326:Chemistry Techniques, Synthetic; D007202:Indicators and Reagents; D008301:Maleimides / Q000138:chemical synthesis / Q000737:chemistry*; D063065:Organophosphonates / Q000138:chemical synthesis* / Q000737:chemistry; D010720:Phosphines / Q000138:chemical synthesis / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013890:Thiourea / Q000138:chemical synthesis / Q000737:chemistry*
D007202:Indicators and Reagents; D008301:Maleimides; D063065:Organophosphonates; D010720:Phosphines; D011759:Pyrrolidines; C044646:phosphine; D013890:Thiourea