Leaving group rate ratios in solvolytic displacement reactions. Effect of neighboring sulfur

1987 ◽  
Vol 52 (11) ◽  
pp. 2299-2301 ◽  
Author(s):  
Dionis E. Sunko ◽  
Branko Jursic ◽  
Mladen Ladika
Keyword(s):  
Leaving Group ◽  
Displacement Reactions ◽  
Group Rate ◽  
Rate Ratios

Kinetics of displacement reactions with pyridines as both leaving group and nucleophile

1979 ◽  
pp. 690 ◽  
Author(s):  
Alan R. Katritzky ◽  
Avijit Banerji ◽  
Bahlul S. El-Osta ◽  
Ian R. Parker ◽  
Christopher A. Ramsden
Keyword(s):  
Leaving Group ◽  
Displacement Reactions ◽  
Kinetics Of

ChemInform Abstract: KINETICS OF DISPLACEMENT REACTIONS WITH PYRIDINES AS BOTH LEAVING GROUP AND NUCLEOPHILE

1979 ◽  
Vol 10 (33) ◽  
Author(s):  
A. R. KATRITZKY ◽  
A. BANERJI ◽  
B. S. EL-OSTA ◽  
I. R. PARKER ◽  
C. A. RAMSDEN
Keyword(s):  
Leaving Group ◽  
Displacement Reactions ◽  
Kinetics Of

General Cyclopropane Assembly via Enantioselective Redox-Active Carbene Transfer to Aliphatic Olefins

2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Chemical Space ◽  
Synthetic Approach ◽  
Asymmetric Cyclopropanation ◽  
Redox Active ◽  
Wide Range ◽  
Leaving Group ◽  
Stereoelectronic Properties ◽  
Carbene Transfer

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>

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