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The Reaction of Triphenylmethyl‐substituted Primary and Secondary Phosphines with Phosgene
Author(s) -
Plack Volker,
Goerlich Jens R.,
Fischer Axel,
Schmutzler Reinhard
Publication year - 1999
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/(sici)1521-3749(199912)625:12<1979::aid-zaac1979>3.0.co;2-s
Subject(s) - phosgene , chemistry , medicinal chemistry , dichloromethane , toluene , chlorine , ether , diethyl ether , solvent , organic chemistry
The nature of the products from the reaction of TrtPH 2 ( 1 ) with an equimolar amount of phosgene strongly depends on the solvent. The initial intermediate 2 was isolated from toluene, but lost CO in dichloromethane, and HCl in diethyl ether, yielding TrtP(H)Cl ( 3 ), and (TrtPCO) 2 ( 4 b ), respectively. TrtP(H)Cl ( 3 ) was found to be a halophosphine of amazing stability. Treatment of 3 with excess phosgene led to partial substitution of the P‐bonded proton for C(:O)Cl with formation of 5 , which did not eliminate CO to give TrtPCl 2 . Substitution of chlorine in TrtP(H)Cl ( 3 ) for fluorine or bromine furnished the halophosphines, 6 and 7 . Minute quantities of the diphosphene 8 were formed upon treatment of 3 with NEt 3 or DBU. The course of the reaction between the secondary phosphines Trt(R)PH and phosgene depends on the group R. If R was t‐Bu, formation of a mixture of Trt(t‐Bu)PCl ( 10 ), and t‐BuPCl 2 (resulting from partial cleavage of the P–C‐bond) was observed. Although in the case of R = Ph, the intermediate 12 could be isolated, at elevated temperature HCl was eliminated from 12 , giving Trt(Ph)PCl ( 13 ). The diphosphine (TrtPH) 2 ( 14 ) is inert towards HCl‐free phosgene. In the presence of HCl the P–P‐bond in 14 was cleaved, and upon chlorination of the resulting TrtPH 2 ( 1 ) by phosgene, TrtP(H)Cl ( 3 ) was obtained as the only phosphorus‐containing product.