Please use this identifier to cite or link to this item: https://doi.org/10.1021/jo035634d
Title: Diverse Modes of Reactivity of Dialkyl Azodicarboxylates with P(III) Compounds: Synthesis, Structure, and Reactivity of Products Other than the Morrison-Brunn-Huisgen Intermediate in A Mitsunobu-Type Reaction
Authors: Satish Kumar, N.
Praveen Kumar, K.
Pavan Kumar, K.V.P.
Kommana, P.
Vittal, J.J. 
Kumara Swamy, K.C.
Issue Date: 19-Mar-2004
Citation: Satish Kumar, N., Praveen Kumar, K., Pavan Kumar, K.V.P., Kommana, P., Vittal, J.J., Kumara Swamy, K.C. (2004-03-19). Diverse Modes of Reactivity of Dialkyl Azodicarboxylates with P(III) Compounds: Synthesis, Structure, and Reactivity of Products Other than the Morrison-Brunn-Huisgen Intermediate in A Mitsunobu-Type Reaction. Journal of Organic Chemistry 69 (6) : 1880-1889. ScholarBank@NUS Repository. https://doi.org/10.1021/jo035634d
Abstract: The reactivity of diethyl azodicarboxylate (DEAD)/diisopropyl azodicarboxylate (DIAD) with P(III) compounds bearing oxygen or nitrogen substituents is explored. Compounds with structures quite different from that of Morrison-Brunn-Huisgen intermediate R′3P +N(CO2R)N-(CO2R) (1), observed in the Mitsunobu reaction, have been established by using X-ray crystallography and NMR spectroscopy. Thus reactions with X(6-t-Bu-4-Me-C6H 2O)2P-NH-t-Bu [X = S (8), CH2 (9)] or XP(μ-N-t-Bu)2P-NH-t-Bu [X = Cl (14) or NH-t-Bu (15)] and DEAD/ DIAD lead to phosphinimine-carbamate-type of products X{6-t-Bu-4-Me-C 6H2O}2P{N-t-Bu}{N(CO2R)NH(CO 2R)} [X = S, R = Et (16); X = CH2, R = Et (17); X = CH2, R = i-Pr (18)] or XP(μ-N-t-Bu) 2P(N-t-Bu){N-(CO2-i-Pr)-N(H)(CO2-i-Pr) [X = Cl (19), NH-t-Bu (20)]. Treatment of 19 with 2,2,2-trifluoroethanol afforded the product [(CF3CH2O)P(μ-N-t-Bu)2P +(NH-t-Bu){N(CO2-i-Pr)(HNCO2-i-Pr)}][Cl -1] (21) whose structure is close to one of the intermediates proposed in the Mitsunobu reaction. The isocyanate CH 2(6-t-Bu-4-Me-C6H2O)2P-NCO (10) underwent 1,3-(P,C) cycloaddition with DEAD/DIAD to lead to CH 2(6-t-Bu-4-Me-C6H2O)2P{N(CO 2R)N(CO2R)-C(O)-N} [R = Et (22), i-Pr (23)]. Reaction of 22-23 with 1,1′-bi-2-naphthol or catechol leads to novel tetracoordinate CH2(6-t-Bu-4-Me-C6H2O)2P(2,2′ -OC10H6-C10H6-OH){NC(O)-(CO 2R)NH(CO2R)} [R = Et (24), i-Pr (25)] or pentacoordinate CH2(6-t-Bu-4-Me-C6H2O)2P(1,2-O 2C6H4){NHC(O)-N(CO2R)NH(CO 2R)} [R = Et (26), i-Pr (27)] compounds in which the original NCO residue is retained; this mode of reactivity is quite different from that observed for the MBH betaine 1. In 27, the nitrogen, rather than the oxygen, occupies an apical position of the trigonal bipyramidal phosphorus violating the commonly assumed preference rules for apicophilicity. It is shown that the previously reported azide derivative 3, obtained from the reaction of 11 with DIAD, undergoes a Curtius-type rearrangement to lead to the fused cyclodiphosphazane [{CH2(6-t-Bu-4-Me-C6H 2O)2}P{OC(O-i-Pr)NN(CO2-i-Pr)N}]2 (28); this compound is in equilibrium with its monomeric form in solution at >300 K. Finally, reaction of S(6-t-Bu-4-Me-C6H2O) 2P(OPh) (13) with DIAD gave the hexacoordinate compound S{6-t-Bu-4-Me-C6H2O}2P(OPh){N(CO 2-i-Pr)NC(O-i-Pr)O} (30) with an intramolecular S→P bond. X-ray crystallographic evidence for compounds 16, 19, 21, 22, 25, 27, 28, and 30 has been provided.
Source Title: Journal of Organic Chemistry
URI: http://scholarbank.nus.edu.sg/handle/10635/93626
ISSN: 00223263
DOI: 10.1021/jo035634d
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

49
checked on Sep 12, 2018

WEB OF SCIENCETM
Citations

49
checked on Sep 12, 2018

Page view(s)

35
checked on Sep 7, 2018

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.