Catalyst-free thiophosphorylation of <i>in situ</i> formed <i>ortho</i>-quinone methides
作者:Jeffrey Ash、Jun Yong Kang
DOI:10.1039/d2ob02169b
日期:——
A metal-, chloride reagent and base-free thiophosphorylation reaction of in situ formed ortho-quinone methide (o-QM) to synthesize functionalized thiophosphates has been developed. The reaction is an atom-economical process, producing water as the sole byproduct. (EtO)2P(O)SH functions as both a Brønsted acid and nucleophilic thiolate to produce the o-QM intermediate and the thiophosphate product,
The treatment of o-(N-acylamino)benzyl alcohols (1) with DAST afforded the dehydrative cyclization product, 4H-3,1-benzoxazines (4) and the hydroxy replacement product, o-(N-acylamino)benzyl fluorides (5). The yields of benzoxazines (4) and fluorides (5) depend on the substituents at alpha-position and acyl groups. The treatment of alpha,alpha-diaryl-o-(N-acylamino)benzyl alcohols (1a-c) with DAST yielded benzoxazines (4a-c) exclusively, while that of alpha-monosubstituted o-(N-acylamino)benzyl alcohols (Id-k) with DAST yielded benzoxazines (4d-k) and fluorides (5d-k). In the reaction of o-(N-acylamino)benzyl alcohol (11) with DAST, the formation of fluoride (51) became predominant and that of benzoxazine (41) was suppressed almost completely.
<b>Intramolecular Nucleophilic Participation. The Effect of Certain <b><i>ortho</i></b> Substituents on Solvolysis Rates of Benzyl and Benzhydryl Bromides</b>
作者:Ajaib. Singh、L. J. Andrews、R. M. Keefer
DOI:10.1021/ja00866a024
日期:1962.4
SCHMIDT, R. R.;BEITZKE, B., CHEM. BER., 1983, 116, N 6, 2115-2135