@article{9f05215196474f21b1a047d56c2c6170,
title = "Stereoselective preparation of functionalized tertiary P-chiral phosphine oxides by nucleophilic addition of lithiated tert-butylphenylphosphine oxide to carbonyl compounds",
abstract = "Nucleophilic carbonyl and conjugate addition reactions of configurationally stable lithiated P-chiral tert-butylphenylphosphine oxide with aldehydes and α,β-unsaturated carbonyl compounds occur in good yields with diastereoselectivities ranging from 33 to ≤98%.",
author = "Haynes, {Richard K.} and Lam, {William W.L.} and Yeung, {Lam Lung}",
note = "Funding Information: and phenyl as compared to tert-butyl, t2 It is noteworthy that even for bulky R groups, as in 1-and 2-naphthyl, the predominance of the ul product is maintained, and thus we have a reaction whose stereo-selectivity is tolerant of a wide range of substituents. Diastereoisomeric transition states involving reaction through the re- face of the lithiated (S)-phosphine oxide with the Re- and Si-faces respectively of the aldehyde experience gauche interactions between R on the aldehyde and both the phenyl and tert-butyl substituents, and are likely to be inaccessible. For the conjugate addition reactions, operation of a closed transition state involving the carbonyl group of the cyclic enones is not feasible, and thus an open transition state involving the Re-face of the (S)-phosphine oxide and the Si-face of the enone may be assumed, with the P-OLi ensemble projecting over the ring and the tert-butyl projecting away. To summarize, these reactions involving addition nucleophilic phosphorus to carbonyl electrophiles offer a simple route to a variety of functionalized tertiary phosphine oxides, and hence the corresponding phosphines. A number of the products will provide use as new ligands for asymmetric catalysis. The reactions of lithiated tert-butylphenylphosphine oxide with other electrophiles and the applications to preparation of doubly P-chiral diphosphine oxides as potential precursors to doubly P-chiral diphosphines is reported in the following communication. Acknowledgments: We thank the School of Science, The Hong Kong University of Science and Technology for financial support to RKH (Direct Allocation Grant DAG 94/95.SC07) for this work.",
year = "1996",
month = jul,
day = "1",
doi = "10.1016/0040-4039(96)00952-5",
language = "English",
volume = "37",
pages = "4729--4732",
journal = "Tetrahedron Letters",
issn = "0040-4039",
publisher = "Elsevier",
number = "27",
}