Organocatalytic selenosulfonylation of the C–C doublebond of α,β-unsaturatedketones to construct two contiguous stereogenic centers in an aqueous medium was described. A series of α-selenyl and β-sulfonyl ketones with various functional groups were synthesized in good yields and enantioselectivities with saturated NaCl solution as the solvent. In addition, this protocol had been successfully scaled
Rh-Catalyzed diastereoselective desymmetrization of enone tethered-cyclohexadienones <i>via</i> tandem arylative cyclization
作者:Sandip B. Jadhav、Satish B. Thopate、Jagadeesh Babu Nanubolu、Rambabu Chegondi
DOI:10.1039/c8ob02284d
日期:——
rhodium-catalyzed arylative cyclization of enone tethered-cyclohexadienones has been developed with high efficiency, thus providing cis-fused bicyclic enones in good yields and with excellent diastereoselectivities. Furthermore, this mild transformation has a broad range of substrate scope and excellent functional group tolerance. In addition, bicyclic products have an enone functionality, which can be
An oxidative dearomatization of phenol followed by a dynamic kinetic (DyKat) ketalization/oxa-Michael addition cascade using cinchona alkaloid-based chiral bifunctional amino-squaramide catalysts is reported. A broad array of sterically hindered [5,5]-spiroketals attached to a cyclohexadienone moiety in spiro-fashion is synthesized in an enantiopure form. Further, the methodology was optimized and
An unprecedented enantioselective dissymmetric 1,4- and 1,2-addition of malononitrile to a keto-bisenone followed by an oxa-Michael addition cascade to trap the in situ generated unstable tertiary alcohol have been developed. The quinine-derived amino-squaramide bifunctional organocatalyst worked efficiently and provides the oxa-spiro-[4,4]-nonanes in good yields and excellent diastereo- and enantioselectivities
作者:Tarun Kumar Roy、Sachin S. Gorad、Prasanta Ghorai
DOI:10.1021/acs.orglett.2c00074
日期:2022.3.18
enantio- and diastereoselective spiroketalization of aromatic ketone tethered to ortho-homoformyl and enone moiety via in situ enol formation using quinine derived squaramide organocatalyst to access aromatic [6,5] spiroketals with complete atom economy. Furthermore, aromatic spiroketals undergo Brønsted acid catalyzed Piancatelli type rearrangement to provide dihydronaphtho[1,2-b]furans with retention of
本文公开了一种有效的对映和非对映选择性螺缩酮化,使用奎宁衍生的方酰胺有机催化剂,通过原位形成烯醇,将束缚在邻-高甲酰基和烯酮部分上的芳族酮进行有效的对映选择性和非对映选择性螺缩酮化,从而获得具有完全原子经济性的芳族 [6,5] 螺缩酮。此外,芳族螺缩酮经历布朗斯台德酸催化的 Piancatelli 型重排,以提供保留对映选择性的二氢萘并[1,2- b ]呋喃。