Direct and efficient synthesis of tetrasubstituted allenyl organothiophosphates from propargylic alcohols under catalyst- and additive-free conditions

Abstract

An environment-friendly approach that affords tetrasubstituted allenyl organothiophosphates containing highly congested carbon centers from easily prepared propargylic alcohols and phosphorothioic acids [(RO)2P(O)SH] with water as the only by-product is developed....

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

“…On the basis of the experimental results and previous literatures, [13b,17] a plausible mechanism of this highly chemoselective transformation is proposed in Scheme 5. Initially, the propargylic alcohols 1 undergoes dehydration process promoted by (EtO) 2 P(O)SH to form propargylic carbocation intermediate A , which is then attacked by (EtO) 2 P(O)S − to afford the target product propargyl organothiophosphates 3 .…”

“…It is worth noting that substrates bearing strong electron‐donating groups on aromatic rings could generate diverse allenyl organothiophosphate products. In our previous work, it can be smoothly constructed by using tertiary propargylic alcohols as substrates (Scheme 1c) [13b] …”

Recent Progress in Application of Propargylic Alcohols in Organic Syntheses

“…A variant of the same transformation, tetrasubstituted allenyl organothiophosphates achieved from propargylic alcohols and phosphorothioic acids. [75] The formation of the new CÀ SP bond under catalyst-and additive-free conditions with H 2 O as the sole byproduct are the advantages of this work. Meanwhile, Zhang and Xie et al could perform two different methods by controlling the temperature in mono-and disulfonylation of propargylic alcohols 1 with sodium sulfonates 187 toward synthesizing propargyl sulfones 188 or (E)-allyl, vinyldisulfones 189, respectively (Scheme 81).…”

PCCP‐Catalyzed Synthesis of Tetrasubstituted Allenes Bearing Heteroaromatic Sulfenyl Group**

“…For instance, Yang developed TBHP/TBAI‐mediated preparation of allenyl sulfones [8a] . Wang discovered chiral phosphoric acid (CPA) catalyzed stereoselective synthesis of sulfur‐containing tetrasubstituted allenes [8b] and in 2022, Zhang published synthesis of tetrasubstituted allenylorganothiophosphates from propargylic alcohols under catalyst‐ and additive‐free conditions [8e] . Herein, we wish to report an organocatalytic approach towards tetrasubstitut ed allenes bearing sulfur‐containing heterocyclic units catalyzed by pentacarboxycyclopentadiene (PCCP) derivatives as Brønsted acid catalysts (Figure 1A) which were recognized as efficient catalytic systems [9]…”