Highly Chemoselective Transformation of Secondary Propargylic Alcohols with (EtO)₂P(O)SH

Abstract

A practical and environmentally friendly approach is presented for the efficient construction of propargyl organothiophosphates and allenyl organothiophosphates from easily prepared secondary propargylic alcohols and O, O-diethyl phosphorothioic acid [(EtO) 2 P(O)SH]. The reaction proceeds smoothly in moderate to excellent yields without additional acid promoters or additives under mild conditions with water as the only by-product. The divergent products are selectively obtained depending on substrates bearing different substituents on the aromatic ring. Notably, the developed reaction system can be scaled up to gram quantities.

Cascade Cyclization of 1,5-Diynols and (RO)2P(O)SH to Construct Benzo[b]fluorenyl S-Alkyl Phosphorothioates under Catalyst-Free Conditions

“…The first step of the envisaged cascade cyclization used 3-(2-((4-methoxyphenyl)­ethynyl)­phenyl)-1,1-diphenylprop-2-yn-1-ol 1a and (EtO) 2 P­(O)­SH 2a (p K a : 1.49 in water) as model substrates. The reaction was performed in CH 3 CN at 60 °C for 2 h without an additional catalyst (Table ).…”

Direct Synthesis of Benzo[b]fluorenyl Thiophosphates via Tandem Cyclization of Diynols with (RO)2P(O)SH

“…Recently, we developed an efficient strategy for the direct synthesis of allenyl organothiophosphates from propargylic alcohols under catalyst- and additive-free conditions (Scheme ). Based on our ongoing interest in the cascade reactions of propargylic alcohols, ,, we envisioned that (RO) 2 P­(O)­SH might serve as a nucleophile and acid-promoter in the tandem cyclization of diynols, which could provide an efficient approach for the one-pot construction of benzo­[ b ]­fluorenyl thiophosphates (Scheme ). Organophosphorothioates bear the distinct functional group C-SP­(O)­(OR) 2 , which has been regarded as an important functional group, including bioactivity in the fields of pharmaceuticals and agrochemicals .…”