A Biocatalytic Approach to Synthesizing Optically Active Orthogonally Protected trans-Cyclopentane-1,2-Diamine Derivatives

Efficient Tandem Process for the Catalytic Deprotection of N-Allyl Amides and Lactams in Aqueous Media: A Novel Application of the Bis(allyl)–Ruthenium(IV) Catalysts [Ru(η3:η2:η3-C12H18)Cl2] and [{Ru(η3:η3-C10H16)(μ-Cl)Cl}2]

An operationally simple and highly efficient methodology for the removal of the allyl protecting group in amides and lactams has been developed by using the commercially available bis(allyl)-ruthenium(IV) catalysts [Ru(eta(3):eta(2):eta(3)-C(12)H(18))Cl(2)] (C(12)H(18)=dodeca-2,6,10-triene-1,12-diyl) and [{Ru(eta(3):eta(3)-C(10)H(16))(micro-Cl)Cl}(2)] (C(10)H(16)=2,7-dimethylocta-2,6-diene-1,8-diyl). The tandem process, which takes place in aqueous media and proceeds in a one-pot manner, involves the initial isomerization of the C=C bond of the allyl unit and subsequent oxidative cleavage of the resulting enamide.

Highly Selective Enzymatic Kinetic Resolution of Primary Amines at 80 °C: A Comparative Study of Carboxylic Acids and Their Ethyl Esters as Acyl Donors

Optimization of the kinetic resolution of 2-amino-4-phenyl-butane was achieved at 80 degrees C using CAL-B-catalyzed aminolysis of carboxylic acids and their ethyl esters. The reactions carried out with long chain esters and the corresponding acids as acyl donors proceeded with remarkably high enantioselectivity. The use of carboxylic acids as acylating agents led to a marked acceleration of the reaction rate compared to their ester counterparts. Lauric acid led to enantiomeric excesses superior to 99.5% for both the remaining amine and the corresponding lauramide at 50% conversion (reached in 3 h). These optimized conditions were applied to the resolution of a series of aliphatic and benzylic amines.