Traversing Steric Limitations by Cooperative Lewis Base/Palladium Catalysis: An Enantioselective Synthesis of α‐Branched Esters Using 2‐Substituted Allyl Electrophiles
作者:Kevin J. Schwarz、Colin M. Pearson、Gabriel A. Cintron‐Rosado、Peng Liu、Thomas N. Snaddon
DOI:10.1002/anie.201803277
日期:2018.6.25
Cooperative catalysis enables the direct enantioselective α‐allylation of linear prochiral esters with 2‐substituted allyl electrophiles. Critical to the successful development of the method was the recognition that metal‐centered reactivity and the source of enantiocontrol are independent. This feature is unique to simultaneous catalysis events and permits logical tuning of the supporting ligands
Cyclization of 2-Alkynylallyl Alcohols to Highly Substituted Furans by Gold(I)-Carbene Complexes
作者:A. Stephen K. Hashmi、Tobias Häffner、Matthias Rudolph、Frank Rominger
DOI:10.1002/ejoc.201001479
日期:2011.2
Various 2-alkynylallylalcohols were synthesized by a generally applicable Sonogashira coupling protocol. Subsequent gold-catalyzed transformation was investigated. The use of AuI catalysts bearing carbene ligands, of either the N-heterocyclic carbene or nitrogen acyclic carbene type, delivered the desired products with low catalyst loadings and under very mild reaction conditions. A broad array of
Borostannylation of Alkynes and Enynes. Scope and Limitations of the Reaction and Utility of the Adducts
作者:Ramakrishna Reddy Singidi、T. V. RajanBabu
DOI:10.1021/ol100824f
日期:2010.6.4
of the products derived from catalyzed vicinal syn-additions to alkynes. The isolation of a variety of such adducts derived from alkynes (and also from hitherto unreported additions to 1,3-enynes) as stable boron pinacolates is reported. Examples of the applications of resulting products in tandem cross-coupling reactions and as dienes in Diels−Alder reactions are illustrated.
Welwitindolinone C synthetic studies. Construction of the welwitindolinone carbon skeleton via a transannular nitrone cycloaddition
作者:David B. Freeman、Alexandra A. Holubec、Matthew W. Weiss、Julie A. Dixon、Akio Kakefuda、Masami Ohtsuka、Munenori Inoue、Rishi G. Vaswani、Hidenori Ohki、Brian D. Doan、Sarah E. Reisman、Brian M. Stoltz、Joshua J. Day、Ran N. Tao、Noah A. Dieterich、John L. Wood
DOI:10.1016/j.tet.2010.04.131
日期:2010.8
Described is the construction of the N-methylwelwitindolinone C core via an efficient strategy that employs a sequential rhodium carbenoid-mediated O-H insertion, Claisen rearrangement and transannular [3+2] nitrone cycloaddition. (C) 2010 Elsevier Ltd. All rights reserved.
A Practical Method for the Synthesis of 2-Alkynylpropenals
作者:Charnsak Thongsornkleeb、Rick L. Danheiser
DOI:10.1021/jo047869a
日期:2005.3.1
A general method for the preparation of 2-alkynyl acroleins is described beginning with vinyl iodide 5 and involving a combination of Sonogashira coupling and Dess-Martin oxidation. Critical to the success of this approach is the use of a special workup procedure for the oxidation step. The resultant enynals participate in a variety of addition reactions including aldol condensations and reactions with organolithium compounds.