Kinetic studies of a vinylcyclopropane (VCP) cycloaddition, catalyzed by peptide-based thiyl radicals, are described. Reactions were analyzed by using reaction progress kinetic analysis, revealing that ring-opening of the VCP is both rate- and enantio-determining. These conclusions are further corroborated by studies involving racemic and enantiopure VCP starting material. Noncovalent interactions play key roles throughout: both the peptide catalyst and VCP exhibit unproductive self-aggregation, which appears to be disrupted by binding between the catalyst and VCP. This in turn explains the requirement for the key catalyst feature, a substituent at the 4-position of the proline residue, which is required for both turnover/rate and selectivity.

We have demonstrated that small, modular,t etrameric peptides featuring the Lewis-basic residue b-dimethylaminoalanine (Dmaa) are capable of atroposelectively coupling naphthols and ester-bearing quinones to yield non-C 2 -symmetric BINOL-type scaffolds with good yields and enantioselectivity.T he study culminates in the asymmetric synthesis of backbone-substituted scaffolds similar to 3,3'-disubstituted BINOLs,s uch as (R)-TRIP,w ith good (94:6 e.r.)t oe xcellent (> 99.9:0.1 e.r.)e nantioselectivity after recrystallization, and ad iastereoselective net arylation of the minimally modified nonsteroidal anti-inflammatory drug (NSAID) naproxen. Scheme 1. Approaches toward construction of enantioenriched atropisomers through naphthol-quinone coupling.

Recent years have witnessed the proliferation of worldwide efforts towards developing technologies for enabling smart cities, to improve the quality of life for citizens. These smart city solutions are typically deployed across large spatial regions over long time scales, generating massive volumes of data. An efficient way of data retrieval is thus required, for post-processing of the data -such as for analytical and visualization purposes.In this paper, we propose a data prefetching and caching algorithm based on Bayesian inference, for the retrieval of data in large-scale smart city applications. A brute-force approach is used to determine the optimal weight correction factor in the proposed prefetching algorithm. We evaluate the optimized Bayesian prefetching algorithm against the Naïve and Random prefetch baselines, using both simulated and actual data usage patterns. Results show that the Bayesian approach can achieve up to 48.4% reductions in actual user-perceived application delays during data retrieval. 978-1-4799-8055-0/15/$31.00 ©2015 IEEE

Herein we report an organocatalytic enantioselective functionalization of heterocyclic carboxaldehydes via the Pictet-Spengler reaction. Through careful pairing of novel squaramide and Brønsted acid catalysts,o ur method tolerates ab readth of heterocycles,e nabling preparation of as eries of heterocycle conjugated b-(tetrahydro)carbolines in good yield and enantioselectivity.Careful selection of carboxylic acid cocatalyst is essential for toleration of av ariety of regioisomeric heterocycles.U tility is demonstrated via the three-step stereoselective preparation of pyridine-containing analogues of potent selective estrogen receptor downregulator and U.S. FDAa pproved drug Tadalafil.

We have demonstrated that small, modular, tetrameric peptides featuring the Lewis‐basic residue β‐dimethylaminoalanine (Dmaa) are capable of atroposelectively coupling naphthols and ester‐bearing quinones to yield non‐C2‐symmetric BINOL‐type scaffolds with good yields and enantioselectivity. The study culminates in the asymmetric synthesis of backbone‐substituted scaffolds similar to 3,3′‐disubstituted BINOLs, such as (R)‐TRIP, with good (94:6 e.r.) to excellent (>99.9:0.1 e.r.) enantioselectivity after recrystallization, and a diastereoselective net arylation of the minimally modified nonsteroidal anti‐inflammatory drug (NSAID) naproxen.