15790-86-0Relevant articles and documents
Direct Conversion of β,γ-Unsaturated Esters into Lactones Induced by TMS-I
Piva, Olivier
, p. 13687 - 13696 (1994)
β,γ-unsaturated esters readily prepared by photodeconjugation are converted in one step into butanolides by treatment with TMS-I.The reaction has been extended to the access to α-alkylidene lactones.
The efficient synthesis of the optically active β-hydroxyl-γ- butyrolactone derivatives
Wang, Jin Xin,Li, Ying,Zhang, Chao Xin
, p. 1183 - 1187 (2003)
The optically active β-hydroxyl-γ-butyrolactones were synthesized from nonchiral starting material by employing reductive cleavage reaction, sharpless asymmetric epoxidation and dihydroxylation, and Lewis acid-catalysed cyclization as key steps. This strategy can be used to prepare many chiral β-hydroxyl-γ-butyrolactone analogues.
Moppett,Sutherland
, p. 3040 (1968)
-
Breuer,Bannet
, p. 1141,1143 (1977)
-
Copper-Catalyzed Azide–Ynamide Cyclization to Generate α-Imino Copper Carbenes: Divergent and Enantioselective Access to Polycyclic N-Heterocycles
Chen, Yang-Bo,Deng, Chao,Liu, Rai-Shung,Liu, Xin,Luo, Chen,Wang, Ze-Shu,Ye, Long-Wu,Zhai, Tong-Yi,Zhang, Yi-Ping
supporting information, p. 17984 - 17990 (2020/08/21)
Here an efficient copper-catalyzed cascade cyclization of azide-ynamides via α-imino copper carbene intermediates is reported, representing the first generation of α-imino copper carbenes from alkynes. This protocol enables the practical and divergent synthesis of an array of polycyclic N-heterocycles in generally good to excellent yields with broad substrate scope and excellent diastereoselectivities. Moreover, an asymmetric azide–ynamide cyclization has been achieved with high enantioselectivities (up to 98:2 e.r.) by employing BOX-Cu complexes as chiral catalysts. Thus, this protocol constitutes the first example of an asymmetric azide–alkyne cyclization. The proposed mechanistic rationale for this cascade cyclization is further supported by theoretical calculations.
Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination
Dakarapu, Udaya Sree,Bokka, Apparao,Asgari, Parham,Trog, Gabriela,Hua, Yuanda,Nguyen, Hiep H.,Rahman, Nawal,Jeon, Junha
supporting information, p. 5792 - 5795 (2015/12/11)
A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner-Wadsworth-Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in situ. Subsequent deprotonative metalation of phosphonate esters followed by HWE with aldehydes furnishes enoates. This operationally convenient, mechanistically unique protocol converts the traditionally challenging aryl, alkenyl, and alkynyl esters to homologated enoates at room temperature within a single vessel.
