A New Method for the Deprotection of Benzyl Ethers or the Selective Protection of Alcohols

Visible‐Light Hypervalent Iodide Carboxylate Photo(trifluoro)methylations and Controlled Radical Polymerization of Fluorinated Alkenes

“…Although HVICs are predominantly used in oxidations, [24] alkyl radicals derived from their thermal-or UV-induced decarboxylation can add to alkenes or alkylate aromatics. [27] With I 2 , HVICs mediate the hypoiodite reaction [24][25][26][27][28] of alcohols, [27][28][29] acids, [27] and amines [27] towards R-Y-I, [29][30][31] which photolyzes [32] to R-YC (Y = O, COO, NH). However, the potential of IDAB and IFAB as radical initiators [33] remains largely ignored, [34,35] and there are no reports on HVICs as well-defined CX 3 C or CX 3 I sources or as initiators for FMs.…”

“…CX 3 COOI (quantitatively obtained from fast, dark, room-temperature reactions of I 2 [24][25][26][27][28][29][30][31][32]42] or R alk -I [43,44] with IDAB or IFAB) affects aromatic iodinations, [24][25][26] alkene iodoacetoxylations, [42] and may oxidize R alk I to CX 3 COOR alk . [43,44] However, while R Alk,Ar CH 2 COOI hypoiodides are stable in the dark, [44] the weak O À I bond, [40] and strong COOI chromophore [44] enable efficient visible light photolysis, [29,30,42,44] where the R-independent rate-determining O-I homolysis, followed by fast decarboxylation [27,39] and I 2 trapping, provides R alk I [27,28,32] within a solvent cage. [44] Consequently, RCOOIs mediate photohalodecarboxylative Hunsdieker-like HVIC reactions with R-I [43,45] or I 2 , [24-28, 32, 44] which have not yet been used in TFMs or polymerizations.…”

“…However, only free radical polymerizations (Figure S10) and no iodine chain ends (Figure S9a) resulted for IDAB and DMPI, while IFAB afforded IDT-CRP (Figure 2), PVDF-I, (Figure S9) and a three times faster polymerization without an induction time (Figure S10). This indicates that all I 2 was rapidly depleted in a fast HVIC [24][25][26][27][28][29][30][31][32]42] reaction [Eqs. ( 5) and (5')], where the resulting CX 3 COOI was subsequently con-sumed by photo- [27][28][29][30][31][32]44] and CX 3 C induced decarboxylation to CX 3 I [Eqs.…”

“…This indicates that all I 2 was rapidly depleted in a fast HVIC [24][25][26][27][28][29][30][31][32]42] reaction [Eqs. ( 5) and (5')], where the resulting CX 3 COOI was subsequently con-sumed by photo- [27][28][29][30][31][32]44] and CX 3 C induced decarboxylation to CX 3 I [Eqs. (4d) and ( 6)].…”

Regioselective Anomeric O‐Benzyl Deprotection in Carbohydrates

“…In this context, benzyl protection for non‐anomeric hydroxyl function in oligosaccharide synthesis is perhaps, a necessary scenario. Interestingly, a couple of methods have been reported for the regioselective removal of the benzyl protecting group from non‐anomeric positions [6,7] . However, when it comes to anomeric position, benzyl as a protective group did not get much application in oligosaccharide synthesis.…”