Macrocycles can restrict the rotation of substituents through steric repulsions, locking in conformations that provide or enhance the activities of pharmaceuticals, agrochemicals, aroma chemicals, and materials. In many cases, the arrangement of substituents in the macrocycle imparts an element of planar chirality. The difficulty in predicting when planar chirality will arise, as well as the limited number of synthetic methods to impart selectivity, have led to planar chirality being regarded as an irritant. We report a strategy for enantio- and atroposelective biocatalytic synthesis of planar chiral macrocycles. The macrocycles can be formed with high enantioselectivity from simple building blocks and are decorated with functionality that allows one to further modify the macrocycles with diverse structural features.

Alkynyl sulfides can be prepared via dehydrohalogenation, nucleophilic and electrophilic thiol alkynylation and catalytic C_sp–S bond formation. Each method presents certain advantages and limitations.

reported by W. C. Still 23 on silica gel obtained from Silicycle Chemical division (40-63 nm; 230-240 mesh). Analytical thin-layer chromatography (TLC) was performed on glassbacked silica gel 60 coated with a fluorescence indicator (Silicycle Chemical division, 0.25 mm, F 254 .). Visualization of TLC plates was performed by UV (254 nm), KMnO 4 or panisaldehyde stains. All mixed solvent eluents are reported as v/v solutions. Concentration refers to removal of volatiles at low pressure on a rotary evaporator. All reported compounds were homogeneous by thin layer chromatography (TLC) and by 1 H NMR spectroscopy. NMR spectra were taken in deuterated CDCl 3 using Bruker AV-300, AV-400 and AV-500 instruments unless otherwise noted. Signals of solvent served as the internal standard (CHCl 3 : δ 7.27 for 1 H, δ 77.0 for 13 C). The 1 H NMR chemical shifts and coupling constants were determined assuming first-order behavior. Multiplicity is indicated by one or more of the following: s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet), br (broad); the list of couplings constants (J) corresponds to the order of the multiplicity assignment. High resolution mass spectrometry (HRMS) was done by the Centre régional de spectrométrie de masse at the Département de Chimie, Université de Montréal on an Agilent LC-MSD TOF system using ESI mode of ionization unless otherwise noted.