Premium
Synthesis of Long‐Chain n ‐Alkylphosphonic Acids by Phosphonylation of Alkyl Bromides with Red Phosphorus and Superbase under Micellar/Phase Transfer Catalysis
Author(s) -
Kuimov Vladimir A.,
Malysheva Svetlana F.,
Belogorlova Natalia A.,
Albanov Alexander I.,
Gusarova Nina K.,
Trofimov Boris A.
Publication year - 2021
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202100067
Subject(s) - chemistry , bromide , alkyl , alkylation , phase transfer catalyst , medicinal chemistry , hydroxide , organic chemistry , micelle , catalysis , inorganic chemistry , aqueous solution
Long‐chain n ‐Alkylphosphonic acids, AlkP(O)(OH) 2 , are synthesized in up to 91 % yield (mostly 40–60 %) by straightforward phosphonylation of alkyl bromides (AlkBr, Alk=C 4 –C 18 ) with red phosphorus (P n ) in the multiphase KOH/H 2 O/toluene system in the presence of 2–10 mol % of cetyltrimethylammonium bromide (CTAB), acting as a micellar/phase transfer catalyst and as a generator/transporter of superbasic hydroxide anions, the intermediate potassium phosphinates being in situ oxidized/neutralized by nitric acid. The key steps of the phosphonylation mechanism are the P−P bond cleavage of P n polymeric molecules by superbasic − OH anions, dissolved in the CTAB micelles, and phase transfer of polyphosphide anions to the organic phase and their alkylation with AlkBr.