A series of 4-halophosphaisocoumarins were prepared with high regioselectivity in good to excellent yields under mild conditions by the reaction of 2-(1-alkynyl)phenylphosphonic acid diesters with I2 in CHCl3 or ICl in CH2Cl2, or by the reaction of 2-(1-alkynyl)phenylphosphonic acid monoesters with NBS or NCS in DMF. Whether the alkynylphosphonates could cyclize or not was affected by the substituents
通过2-(1-炔基)
苯基膦酸二酯与I 2在CHCl 3中或ICl在CH 2 Cl 2中的反应,或通过在2-(1-炔基)
苯基膦酸单酯与
NBS或
NCS在
DMF中的反应 炔基
膦酸酯是否可以环化受取代基,反应溶剂和亲电试剂的影响。讨论了这种反应的原理。