Synthesis 2022; 54(17): 3801-3808
DOI: 10.1055/a-1689-3626
special topic
Special Issue in memory of Prof. Ferenc Fülöp

On the Synthesis of a Novel Chiral Phosphorodiamidic Acid Containing­ the α-Phenylethyl Moiety: Insights on its Conformation and Reactivity

Carlos Cruz-Hernández
a   Departamento de Química, Centro de Investigación y de Estudios Avanzados, Avenida IPN No. 2508, 07360 Ciudad de México, México
,
Eusebio Juaristi
a   Departamento de Química, Centro de Investigación y de Estudios Avanzados, Avenida IPN No. 2508, 07360 Ciudad de México, México
b   El Colegio Nacional, Luis González Obregón No. 23, Centro Histórico, 06020 Ciudad de México, México
› Author Affiliations
We are grateful to Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico) for financial support via grants 220945, 3240029 and A1-S-44097. We are also grateful to the SEP-CINVESTAV Fund via grant 126.


Dedicated to the memory of Professor Ferenc Fülöp, friend and colleague

Abstract

A few years ago, the synthesis of chiral phosphoric acids supported on chiral BINOL frameworks was accomplished by T. Akiyama and M. Terada. Subsequent relevant applications demonstrated the importance of chiral phosphoric acids as privileged chiral inducers in asymmetric organocatalysis. In the present report, we discuss the development of novel chiral phosphorodiamidic acids derived from C 2-symmetric trans-1,2-diaminocyclohexane aliphatic frameworks. The preparation of the new chiral Brønsted acids, based on the intermediacy of a 1,3,2-diheterophospholan-2-oxide moiety, turned out to be challenging since several plausible synthetic methodologies proved to be ineffective. Furthermore, the five-membered heterocyclic moiety turned out to be easily hydrolyzed when exposed to nucleophilic alcohols or water. Complementary to the successful multistep synthesis reported here, it was possible to obtain crystals of the key precursor of the desired phosphorodiamidic acid, which proved suitable for X-ray diffraction analysis and hence to establish important conformational characteristics of the novel heterocycle.

Supporting Information



Publication History

Received: 19 September 2021

Accepted after revision: 08 November 2021

Accepted Manuscript online:
08 November 2021

Article published online:
12 January 2022

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