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Organophosphorus Compounds, 111 Phospha Ene Reactions of a P ‐Chlorophosphaalkene as a Versatile and Powerful Enophile Building Block
Author(s) -
Mackewitz Thomas W.,
Regitz Manfred
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619960307
Subject(s) - chemistry , allene , ene reaction , trimethylsilyl , adduct , yield (engineering) , double bond , methylene , lithium (medication) , medicinal chemistry , propynyl , organic chemistry , catalysis , medicine , materials science , metallurgy , endocrinology
[Bis(trimethylsilyl)methylene]chlorophosphane ( 1 ) has proved to act as an extremely reactive enophile in phospha ene reactions with all‐carbon enes of differing constitutions and so provides a general approach to β,γ‐unsaturated chlorophosphanes. Thus, for example, 1 reacts even at room temperature or slightly elevated temperatures with the terminal alkenes 6a–c , the methylenecycloalkanes 6d, e, h , and the cycloalkenes 6f, g to furnish the corresponding allyl‐substituted chlorophosphanes 7a–h . Dimethylallene ( 8 ) undergoes addition to 1 to yield the phosphanyl‐substituted buta‐1,3‐diene 9 whereas allene ( 10 ) itself reacts with 1 by way of a previously unknown phospha ene reaction to give the propynyl‐substituted chlorophosphane 11 . By contrast, the (chlorophosphanyl)allene 13 results from the reaction of 1 with but‐2‐yne ( 12 ). All of these group transfer reactions proceed chemo‐ and regioselectively with P/C bond formation. The constitutions of all the phospha ene adducts, which were isolated in satisfactory to good yields after purification by distillation, were unequivocally confirmed by analytical and spectroscopic methods.