Diastereoselective synthesis of polysubstituted cyclopentanols and cyclopentenes containing stereogenic centers via domino Michael/cyclization reaction

Chemoselective and one-pot synthesis of novel coumarin-based cyclopenta[c]pyrans via base-mediated reaction of α,β-unsaturated coumarins and β-ketodinitriles

“…The mechanism of the rst step including b-ketodinitriles formation is known. [32][33][34][35][36][37][38]…”

“…The mechanism of the first step including β-ketodinitriles formation is known. 32–38 Based on experimental observations, a plausible mechanism for the formation of coumarin-based cyclopenta[ c ]pyrans is depicted in Scheme 3 . Iinitially, Et 3 N deprotonates β-ketodinitrile 1 to form anion intermediate 4.…”

Piperidine‐Mediated [3+2] Cyclization of Donor‐Acceptor Cyclopropanes and β‐Nitrostyrenes: Access to Polysubsituted Cyclopentenes with High Diastereoselectivity

“…Many investigations showed that substituted malononitriles are identified as a class of versatile building blocks with high reactivity, [7] which have been extensively applied in the synthesis of target compounds. For example, Balalaie's group reported an one‐pot three‐component reaction of β‐nitrostyrenes, malononitrile and 2‐bromo‐1‐(4‐methoxyphenyl)ethan‐1‐one in basic media at room temperature to provide cyclopentene carboxamides [5b] . Soon afterwards Han and co‐workers used phenacylmalononitriles as substrates to react with β‐nitrostyrenes, supplying a method to functionalized cyclopentenes having an allylic quaternary carbon center bearing both cyano and carboxamide groups with high yields and high diastereoselectivity [8] .…”

An environmentally friendly approach for the synthesis of quinazolinone sulfonamide

“…In continuation of our research work [54][55][56][57][58][59][60][61][62][63][64], we report herein the synthesis of quinazolinone sulfonamides through the four-component reaction of isatoic anhydride, hydrazine hydrate, benzaldehyde derivatives, and saccharin under solvent-free conditions using propylsulfonic acid …”