Ti-direct, powerful, stereoselective aldol-type additions of esters and thioesters to carbonyl compounds: application to the synthesis and evaluation of lactone analogs of jasmone perfumes
thiophenyl esters or thioaryl esters with aldehydes and ketones was performed (total 46 examples). The present method is advantageous from atom-economical and cost-effective viewpoints; good to excellent yields, moderate to good syn-selectivity, substrate variations, reagent availability, and simple procedures. Utilizing the present reaction as the key step, an efficient short synthesis of three lactone
Isolable and Readily Handled Halophosphonium Pre-reagents for Hydro- and Deuteriohalogenation
作者:Florian T. Schevenels、Minxing Shen、Scott A. Snyder
DOI:10.1021/jacs.6b12653
日期:2017.5.10
and acid-sensitive moieties, particularly polyenes prone to cyclization. The process is also challenging when conducted on a small scale, and moreover, methods for the addition of their deuterated counterparts typically require special techniques, especially when control of stoichiometry is required. Herein is described a readily synthesized and handled reagent class which can accomplish the controlled
作者:Daniel H. Paull、Chao Fang、James R. Donald、Andrew D. Pansick、Stephen F. Martin
DOI:10.1021/ja305117m
日期:2012.7.11
highly enantioselectivebromolactonizations of a number of structurally distinct unsaturated acids. Like some known catalysts, this catalyst promotes highly enantioselectivebromolactonizations of 4- and 5-aryl-4-pentenoic acids, but it also catalyzes the highly enantioselectivebromolactonizations of 5-alkyl-4(Z)-pentenoic acids. These reactions represent the first catalytic bromolactonizations of alkyl-substituted
Enantioselective Halolactonization Reactions using BINOL-Derived Bifunctional Catalysts: Methodology, Diversification, and Applications
作者:Daniel W. Klosowski、J. Caleb Hethcox、Daniel H. Paull、Chao Fang、James R. Donald、Christopher R. Shugrue、Andrew D. Pansick、Stephen F. Martin
DOI:10.1021/acs.joc.8b00490
日期:2018.6.1
A general protocol is described for inducing enantioselective halolactonizations of unsaturated carboxylic acidsusing novel bifunctional organic catalysts derived from a chiral binaphthalene scaffold. Bromo- and iodolactonization reactions of diversely substituted, unsaturated carboxylic acids proceed with high degrees of enantioselectivity, regioselectivity, and diastereoselectivity. Notably, these
Ruthenium- and rhodium-catalyzed intramolecular C–H/olefin coupling reactions of 1-(2-pyridyl)-, 1-(2-imidazolyl)-, and 1-(2-oxazolyl)-1,5-dienes proceeded in a regiospecific manner to give 5-membe...