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An effective stereocontrolled synthesis of the HIV protease inhibitor Nelfinavir is reported. Two transformations were identified crucial for achieving success: the formation of a densely functionalized α-chloroketone via the homologation of a Weinreb amide with chloromethyllithium (LiCH2Cl), followed by its erythro selective reduction into the corresponding chiral chlorohydrin. A commercially available enzyme P2-C02 was particularly well suited for this purpose, affording the key alcohol (in an excellent 99% de), which was then smoothly converted into the active biologically active agent.

α-Fluoromethyl selenoethers were prepared through a sequential one-pot diselenide reduction-fluoromethylation with the fluorinated, highly manipulable C1 source ICH2F. The reaction benefited from the employment of the environmentally friendly solvent MeTHF (2-methyltetrahydrofuran) which enabled to maximize the efficiency of both steps of the technique. A series of variously functionalized analogues – featuring a remarkable degree of stability imparted by selenium - could be chemoselectively accessed in high yield and purity through an intuitive and experimentally simple protocol.

The transfer of a α-methyl phenylseleno carbanion to variously functionalized N-aryl and N-sulfonyl imines is reported. The fast selenium-lithium exchange conducted on a diselenoacetal with n-BuLi enables the generation of the attacking homologative nucleophile under chemoselective conditions preserving concomitant potentially sensitive functionalities to the lithiating conditions. Uniformly high yields were observed, thus establishing a valuable and conceptually simple approach to the title compounds.

A chemoenzymatic Dynamic Kinetic Resolution (DKR) of unsymmetrical benzoins (Ar1≠Ar2) has been carried out, by using Pseudomonas stutzeri lipase stereorecognition pattern. After studying this lipase behaviour, a high preference towards acylation of those benzoins containing substituents in the phenyl ring rather than in the benzoyl moiety was observed. This fact allowed the development of the DKR process of this kind of substrates, avoiding the accumulation of secondary products derived from the in situ racemization mediated by Shvo’s catalyst action, and allowing the synthesis of enantiopure unsymmetrical benzoins acetates (not previously described) in very good yields (60–95%) and excellent enantiomeric excess values (always >99%).

Very high regioselective 1,2-addition of organolithiums to α,β-unsaturated carbonyl-like compounds (ketones, aldehydes, and imines) in the presence of LiBr was achieved by carrying out reactions in the sustainable solvent 2-methyltetrahydrofuran. Excellent yields (in isolated product) of allylic alcohols and allylic amines were recovered under a simple experimental procedure at 0 °C.