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Transient Dipnictyl Analogues of Acrylamides, R−E=E′−CONR 2 , and a Related Diphosphadigalletane from Na[OCP] and (R 2 N) 2 ECl (E, E′=P, As, Ga)
Author(s) -
Borger Jaap E.,
Le Corre Grégoire,
Mei Yanbo,
Suter Riccardo,
Schrader Erik,
Grützmacher Hansjörg
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201806116
Subject(s) - chemistry , reactivity (psychology) , cycloaddition , amine gas treating , medicinal chemistry , alkyl , crystal structure , stereochemistry , crystallography , catalysis , organic chemistry , medicine , alternative medicine , pathology
The reaction of Na[OCP] with (R 2 N) 2 ECl (E=P or As; R=alkyl) granted direct access to transient amine‐substituted diphospha‐ and arsaphospha‐acrylamide analogues, (R 2 N)E=P(CONR 2 ) 1 . Their facile formation allowed for a comprehensive reactivity study. Dimerization yielded the four‐membered rings (R 2 N) 2 E 2 P 2 (CONR 2 ) 2 , whereas in the presence of excess Na[OCP], a stepwise [2+2] cycloaddition occured, leading to the sodium salts of carboxotripnictides [(R 2 N)EP 2 CO(CONR 2 )] − . These salts served as a reservoir of 1 , either by extrusion of Na[OCP] or by reaction with the appropriate (R 2 N) 2 ECl, giving the [4+2]‐cycloaddition products (R 2 N)EP(C 6 H 10 )(CONR 2 ) in the presence of 2,3‐dimethylbutadiene. The formal conjugate addition product K[( t BuO)(R 2 N)PP(CONR 2 )] was obtained by reaction of Na[(R 2 N)PP 2 CO(CONR 2 )] with t BuOK. In addition, a rare diphosphadigalletane with a ladder‐type (R 2 N) 2 Ga 2 P 2 (CONR 2 ) 2 core was isolated from the reaction of Na[OCP] with (R 2 N) 2 GaCl (R=alkyl). The unprecedented pnictogenyl carboxamide compounds were thoroughly characterized, including single‐crystal X‐ray structure determinations, and mechanisms for their formation were investigated by DFT calculations.