Diphosphine-catalyzed mixed double-Michael reaction: a unified synthesis of indolines, dihydropyrrolopyridines, benzimidazolines, tetrahydroquinolines, tetrahydroisoquinolines, dihydrobenzo-1,4-oxazines, and dihydrobenzo-3,1-oxazines.
Seven different types of benzannulated N-heterocycles-indolines, dihydropyrrolopyridines, benzimidazolines, dihydrobenzo-3,1-oxazines, benzomorpholines, tetrahydroquinolines, and tetrahydroisoquinolines-can be obtained from simple dinucleophiles and electron-deficient acetylenes in one synthetic step. This powerful methodology was made possible through the use of diphenylphosphinopropane (DPPP) as the catalyst, with acetic acid and sodium acetate used as additives in some cases. The benzannulated N-heterocycles were isolated in excellent yields under mild metal-free conditions; they were purified without the need for aqueous workups.
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
Vardhineedi
V
Sriramurthy
Ohyun
O
Kwon
D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D010078:Oxazines / Q000138:chemical synthesis* / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry*; D011407:Propane / Q000031:analogs & derivatives* / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry; D044005:Tetrahydroisoquinolines / Q000138:chemical synthesis* / Q000737:chemistry
D001562:Benzimidazoles; D007211:Indoles; D010078:Oxazines; D010720:Phosphines; D011725:Pyridines; D011804:Quinolines; D044005:Tetrahydroisoquinolines; C467590:1,3-bis(diphenylphosphino)propane; C057812:indoline; C542964:1,2,3,4-tetrahydroquinoline; D011407:Propane