scholarly journals Recent progress toward the asymmetric synthesis of carbon-substituted piperazine pharmacophores and oxidative related heterocycles

2020 ◽  
Vol 11 (7) ◽  
pp. 745-759
Author(s):  
Plato A. Magriotis

The piperazine drugs are mostly N-substituted compared to only a few C-substituted drugs. To explore this unknown chemical space, asymmetric syntheses of C-substituted piperazines is the subject of this review.

2014 ◽  
Vol 86 (7) ◽  
pp. 1227-1235 ◽  
Author(s):  
Ai-E Wang ◽  
Pei-Qiang Huang

AbstractIn this report, we present recent progress in synthetic methodologies based on three heterocyclic chiral building blocks developed from our laboratories. The potential of these chiral building block-based methods in the concise asymmetric synthesis of alkaloids and medicinally interesting molecules has been demonstrated by the total syntheses of 8-aza-prostaglandin E1, 11-hydroxylated analogues of the lead compounds CP-734432 and PF-04475270, (+)-castanospermine, (+)-1-epi-castanospermine, 7-deoxy-6-epi-castanospermine as well as 9-epi-sessilifoliamide J.


2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>


ChemInform ◽  
2010 ◽  
Vol 33 (51) ◽  
pp. no-no
Author(s):  
J. Blanchet ◽  
M. Bonin ◽  
L. Micouin

Author(s):  
Amandeep Singh Bhatia ◽  
Renata Wong

Quantum computing is a new exciting field which can be exploited to great speed and innovation in machine learning and artificial intelligence. Quantum machine learning at crossroads explores the interaction between quantum computing and machine learning, supplementing each other to create models and also to accelerate existing machine learning models predicting better and accurate classifications. The main purpose is to explore methods, concepts, theories, and algorithms that focus and utilize quantum computing features such as superposition and entanglement to enhance the abilities of machine learning computations enormously faster. It is a natural goal to study the present and future quantum technologies with machine learning that can enhance the existing classical algorithms. The objective of this chapter is to facilitate the reader to grasp the key components involved in the field to be able to understand the essentialities of the subject and thus can compare computations of quantum computing with its counterpart classical machine learning algorithms.


1960 ◽  
Vol 64 (589) ◽  
pp. 1-23
Author(s):  
W. P. Smith

The Fifteenth British Commonwealth Lecture “Some Recent Progress in Air Survey with Particular Reference to Newly- Developed Territories" was given by W. P. Smith, M.B.E., B.A., F.R.I.C.S. before the Royal Aeronautical Society at the Institution of Mechanical Engineers on 19th November 1959. Mr. Peter G. Masefield, M.A., F.R.Ae.S., Hon.F.I.A.S., President of the Society, presided. Introducing the Lecturer the President said: This lecture was the second of their four premier named annual lectures. The first was the traditional Wilbur Wright Lecture, the second this Commonwealth Lecture, the third was the Louis Bleriot Lecture and the fourth the Lanchester Memorial Lecture. Five years ago, as many of them would recall, His Royal Highness, Prince Philip, the Duke of Edinburgh, honoured them by giving the Commonwealth Lecture on ”Aviation and the Development of Remote Areas.“He thought that they could say that the subject of Mr. Smith's Commonwealth Lecture was in some ways a projection of the Duke of Edinburgh's lecture, under the title "Some Recent Progress in Air Survey with Particular Reference to Newly- Developed Territories.”Mr. W. P. Smith was a Director and leading light of Fairey Air Surveys Limited. Naturally as befitted a Commonwealth Lecturer, Mr. Smith was a master of his subject—one could almost say that he was “monarch of all he surveys.” He was a Durham man, born in 1920; he was educated at Wellfield School, Durham, and went up to Oxford and took his degree there. During the War, Mr. Smith was in command of Survey Units in the Royal Engineers and after the War he transferred to the Survey Branch of the Control Commission, in Germany. Then, in 1946 he left the Army to join the new Directorate of Colonial Surveys as a Senior Surveyor, and went to West Africa on the Volta River Project. He worked in Africa for a period and then in 1950 he joined Fairey Air Surveys Limited, then known as the Air Survey Company, as many would remember. He was a General Manager then, and was now a Director. So Mr. Smith had spent all his working life dealing with the subject on which he was going to talk about that evening, and in particular, he had been in charge of that vast Kariba Hydro-Electric Survey, on the Zambesi. They could have no one better to talk about Air Survey, and it was said that “life is the art of drawing sufficient conclusions from insufficient premises.” Air Survey, and the sort of things Mr. Smith was going to talk about was, in some ways, a way of filling in some of those insufficiencies.He had much pleasure in calling on Mr. Smith to deliver the Fifteenth British Commonwealth Lecture.


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