Derivatives of α,α,α′,α′-Tetraaryl-2,2-dimethyl-1,3-dioxolan-4,5-dimethanol (TADDOL) containing nitrogen, sulfur, and phosphorus atoms. New ligands and auxiliaries for enantioselective reactions.

Abstract

α,α,α′,α′-Tetraaryl-2,2-dimethyl-1,3-dioxolan-4,5-dimethanols are converted to bicyclic phosphites and phosphonites ( 2a–2e) by reaction with Cl 2PR and Cl 2POR derivatives. - One or both OH groups of the parent TADDOL can be replaced by Cl (→, 4a, 5a), and the halide in turn substituted by azide (→ 4b, 5b), thiocyanide (→ 6), or sulfide (→ 8). Reduction of the azido group(s) to NH 2 and N-alkylation or acylation furnishes a variety of amino alcohols ( 4c–4f) and diamines ( 5c–5f), as well as a bis(trifluoroacetamide) ( 5g). Cyclization of the aminoalcohol ( 4c) produces a bicyclic system ( 7), containing a pyrrolidine ring (structure determination by X-ray diffraction). - The new chiral compounds containing nitrogen and phosphorus atoms might be useful ligands and auxiliaries for enantioselective syntheses.